cover.
Notices © Agilent Technologies, Inc. 20092012 No part of this manual may be reproduced in any form or by any means (including electronic storage and retrieval or translation into a foreign language) without prior agreement and written consent from Agilent Technologies, Inc. as governed by United States and international copyright laws. Manual Part Number 34972-90001 Third Edition, May 2012 Printed in Malaysia Agilent Technologies, Inc. 900 S. Taft Ave.
Safety Notices A CAUTION notice denotes a hazard. It calls attention to an operating procedure, practice, or the like that, if not correctly performed or adhered to, could result in damage to the product or loss of important data. Do not proceed beyond a CAUTION notice until the indicated conditions are fully understood and met. A WARNING notice denotes a hazard.
Safety Symbols Alternating current Frame or chassis terminal Unless otherwise noted in the specifications, this instrument or system is intended for indoor use in an installation category II, pollution degree 2 environment per IEC 61010-1 and 664 respectively. It is designed to operate at a maximum relative humidity of 20% to 80% at 40 °C or less (non-condensing). This instrument or system is designed to operate at altitudes up to 2000 meters, and at temperatures between 0 °C and 55 °C. Standby supply.
34970A Refresh UG.book Page 5 Wednesday, February 17, 2010 12:34 PM Note: Unless otherwise indicated, this manual applies to all serial numbers. The Agilent Technologies 34970A/34972A combines precision measurement capability with flexible signal connections for your production and development test systems. Three module slots are built into the rear of the instrument to accept any combination of data acquisition or switching modules.
34970A Refresh UG.book Page 6 Wednesday, February 17, 2010 12:34 PM The Front Panel at a Glance Denotes a menu key. See the next page for details on menu operation.
34970A Refresh UG.book Page 7 Wednesday, February 17, 2010 12:34 PM The Front-Panel Menu at a Glance Several of the front-panel keys guide you through menus to configure various parameters of the instrument (see previous page). The following steps demonstrate the menu structure using the key. 1. Press the menu key. You are automatically guided to the first level of the menu. Rotate the knob to view the other choices on the first level of the menu.
34970A Refresh UG.book Page 8 Wednesday, February 17, 2010 12:34 PM Display Annunciators SCAN MON VIEW CONFIG ADRS RMT ERROR EXT ONCE MEM (34970A) MEM (34972A) AUTO (34972A) LAST MIN MAX SHIFT 4W OC Scan is in progress or enabled. Press and hold again to turn off. Monitor mode is enabled. Press again to turn off. Scanned readings, alarms, errors, or relay cycles are being viewed. Channel configuration is in progress on displayed channel. Measurement is in progress.
34970A Refresh UG.book Page 9 Wednesday, February 17, 2010 12:34 PM The 34970A Rear Panel at a Glance 1 Slot Identifier (100,200, 300) 2 Ext Trig Input / Alarm Outputs / Channel Advance Input / Channel Closed Output (for pinouts, see pages 99 and 145) 3 RS-232 Interface Connector 4 5 6 7 Power-Line Fuse-Holder Assembly Power-Line Voltage Setting Chassis Ground Screw GPIB (IEEE-488) Interface Connector Use the Menu to: • Select the GPIB or RS-232 interface (see chapter 2).
34970A Refresh UG.book Page 10 Wednesday, February 17, 2010 12:34 PM The 34972A Rear Panel at a Glance ExtT rig / Alarms (5V) US 168520 ICES/NM B-001 ISM-A1 LXI Class C Line: 50/60/400 Hz 100V 120V (127V) 240V 220V (230V) N10149 Fuse: 500mAT (250V) Opt.
34970A Refresh UG.book Page 11 Wednesday, February 17, 2010 12:34 PM BenchLink Data Logger 3 at a Glance The Agilent BenchLink Data Logger 3 software provides a convenient way to collect and analyze your data. The software uses a familiar spreadsheet environment, streamlining your data gathering needs. Simply identify the measurements you want to acquire, initiate the process, and see the data displayed on the computer screen.
34970A Refresh UG.book Page 12 Wednesday, February 17, 2010 12:34 PM The Plug-In Modules at a Glance For complete specifications on each plug-in modules, refer to the module sections in chapter 8.
34970A Refresh UG.book Page 13 Wednesday, February 17, 2010 12:34 PM 34903A 20-Channel Actuator / General-Purpose Switch • 300 V, 1 A actuation and switching • SPDT (Form C) latching relays • Breadboard area for custom circuits • For detailed information and a module diagram, see page 205. Use this module for those applications that require high-integrity contacts or quality connections of non-multiplexed signals.
34970A Refresh UG.book Page 14 Wednesday, February 17, 2010 12:34 PM 34907A Multifunction Module • Two 8-bit Digital Input/Output ports, 400 mA sink, 42 V open collector • 100 kHz Totalize input with 1 Vpp sensitivity • Two 16-bit, ±12 V Calibrated Analog Outputs • For detailed information and module block diagrams, see page 211. Use this module to sense status and control external devices such as solenoids, power relays, and microwave switches.
34970A Refresh UG.book Page 15 Wednesday, February 17, 2010 12:34 PM In This Book Quick Start Chapter 1 helps you get familiar with a few of the instrument’s front-panel features. This chapter also shows how to install the BenchLink Data Logger 3 software. Front-Panel Overview Chapter 2 introduces you to the front-panel menus and describes some of the instrument’s menu features. System Overview Chapter 3 gives an overview of a data acquisition system and describes how parts of a system work together.
34970A Refresh UG.
34970A Refresh UG.
34970A Refresh UG.
34970A Refresh UG.book Page 19 Wednesday, February 17, 2010 12:34 PM Contents Chapter 5 Error Messages Execution Errors 219 Instrument Errors 224 Self-Test Errors 235 Calibration Errors 236 Plug-In Module Errors 239 Chapter 6 Application Programs Example Programs for Excel 7.
34970A Refresh UG.
34970A Refresh UG.
34970A Refresh UG.book Page 22 Wednesday, February 17, 2010 12:34 PM Quick Start One of the first things to do with your instrument is to become acquainted with the front panel. We have written the exercises in this chapter to prepare the instrument for use and help you get familiar with some of its front-panel operations. The front panel has several groups of keys to select various functions and operations. A few keys have a shifted function printed in blue below the key.
34970A Refresh UG.book Page 23 Wednesday, February 17, 2010 12:34 PM Chapter 1 Quick Start To Prepare the Instrument for Use 1 To Prepare the Instrument for Use 1 Check the list of supplied items. Verify that you have received the following items with your instrument. If anything is missing, contact your nearest Agilent Technologies Sales Office or Agilent authorized reseller. • One power cord. 4 • This User’s Guide. • One Service Guide. • Certificate of Calibration (if you ordered the internal DMM).
34970A Refresh UG.book Page 24 Wednesday, February 17, 2010 12:34 PM Chapter 1 Quick Start To Prepare the Instrument for Use 4 Perform a complete self-test. The complete self-test performs a more extensive set of tests than those performed at power-on. Hold down as you turn on the instrument and hold down the key until you hear a long beep. The self-test will begin when you release the key following the beep.
34970A Refresh UG.book Page 25 Wednesday, February 17, 2010 12:34 PM Chapter 1 Quick Start BenchLink Data Logger Software 1 BenchLink Data Logger Software The Agilent BenchLink Data Logger 3 software comes standard with the 34970A/34972A (if the internal DMM is ordered) and provides the basic data logger capabilities. Or, for increased capabilities, purchase the optional Agilent BenchLink Data Logger Pro software.
34970A Refresh UG.book Page 26 Wednesday, February 17, 2010 12:34 PM Chapter 1 Quick Start BenchLink Data Logger Software On-Line Help System The software is shipped with an extensive on-line Help system to help you learn the features of the software as well as troubleshoot any problems that might arise as you are using the software. As you are installing the software, you will notice that the on-line Help system is available in several languages.
34970A Refresh UG.book Page 27 Wednesday, February 17, 2010 12:34 PM Chapter 1 Quick Start To Connect Wiring to a Module 1 To Connect Wiring to a Module 1. Remove the module cover. 2 Connect wiring to the screw terminals. 4 20 AWG Typical 6 mm 3 Route wiring through strain relief. 4 Replace the module cover. Cable Tie Wrap (optional) 5 Install the module into mainframe. Channel Number: Slot Channel Wiring Hints...
34970A Refresh UG.book Page 28 Wednesday, February 17, 2010 12:34 PM Chapter 1 Quick Start To Connect Wiring to a Module Thermocouple DC Voltage / AC Voltage / Frequency Thermocouple Types: B, E, J, K, N, R, S, T See page 351 for thermocouple color codes. 2-Wire Ohms / RTD / Thermistor Ranges: 100 mV, 1 V, 10 V, 100 V, 300 V 4-Wire Ohms / RTD Ranges: 100, 1 k, 10 k, 100 k, 1 M, 10 M, 100 M RTD Types: 0.00385, 0.00391 Thermistor Types, 2.
34970A Refresh UG.book Page 29 Wednesday, February 17, 2010 12:34 PM Chapter 1 Quick Start To Set the Time and Date 1 To Set the Time and Date All readings during a scan are automatically time stamped and stored in non-volatile memory. In addition, alarm data is time stamped and stored in a separate non-volatile memory queue. 1 Set the time of day. 4 Use and to select the field to modify and turn the knob to change the value. You can also edit the AM/PM field. TIME 03:45 PM 2 Set the date.
34970A Refresh UG.book Page 30 Wednesday, February 17, 2010 12:34 PM Chapter 1 Quick Start To Configure a Channel for Scanning To Configure a Channel for Scanning Any channel that can be “read” by the instrument can also be included in a scan. This includes readings on multiplexer channels, a read of a digital port, or a read of the count on a totalizer channel. Automated scanning is not allowed with the RF multiplexer, matrix, actuator, digital output, or voltage output (DAC) modules.
34970A Refresh UG.book Page 31 Wednesday, February 17, 2010 12:34 PM Chapter 1 Quick Start To Configure a Channel for Scanning 1 Note: Press to sequentially step through the scan list and take a measurement on each channel (readings are not stored in memory). This is an easy way to verify your wiring connections before initiating the scan. 3 Run the scan and store the readings in non-volatile memory.
34970A Refresh UG.book Page 32 Wednesday, February 17, 2010 12:34 PM Chapter 1 Quick Start To Copy a Channel Configuration To Copy a Channel Configuration After configuring a channel to be included in the scan list, you can copy that same configuration to other channels in the instrument (including digital channels on the multifunction module). This feature makes it easy to configure several channels for the same measurement.
34970A Refresh UG.book Page 33 Wednesday, February 17, 2010 12:34 PM Chapter 1 Quick Start To Close a Channel 1 To Close a Channel On the multiplexer and switch modules, you can close and open individual relays on the module. However, note that if you have already configured any multiplexer channels for scanning, you cannot independently close and open individual relays on that module. 4 1 Select the channel. Turn the knob until the desired channel is shown on the right side of front-panel display.
970A Refresh UG.book Page 34 Wednesday, February 17, 2010 12:34 PM Chapter 1 Quick Start If the Instrument Does Not Turn On If the Instrument Does Not Turn On Use the following steps to help solve problems you might encounter when turning on the instrument. If you need more help, refer to the 34970A/34972A Service Guide for instructions on returning the instrument to Agilent for service. 1 Verify that there is AC power to the instrument.
34970A Refresh UG.book Page 35 Wednesday, February 17, 2010 12:34 PM Chapter 1 Quick Start If the Instrument Does Not Turn On 1 1 Remove the power cord. Remove the fuse-holder assembly from the rear panel. 2 Remove the line voltage selector from the assembly. 4 Fuse: 500 mAT (for all line voltages) Agilent Part Number: 2110-0458 3 Rotate the line-voltage selector until the correct voltage appears in the window. 4 Replace the fuse-holder assembly in the rear panel.
34970A Refresh UG.book Page 36 Wednesday, February 17, 2010 12:34 PM Chapter 1 Quick Start To Adjust the Carrying Handle To Adjust the Carrying Handle To adjust the position, grasp the handle by the sides and pull outward. Then, rotate the handle to the desired position.
34970A Refresh UG.book Page 37 Wednesday, February 17, 2010 12:34 PM Chapter 1 Quick Start To Rack Mount the Instrument 1 To Rack Mount the Instrument You can mount the instrument in a standard 19-inch rack cabinet using one of three optional kits available. Instructions and mounting hardware are included with each rack-mounting kit. Any Agilent System II instrument of the same size can be rack-mounted beside the 34970A/ 34972A.
34970A Refresh UG.book Page 38 Wednesday, February 17, 2010 12:34 PM Chapter 1 Quick Start To Rack Mount the Instrument To rack mount a single instrument, order adapter kit 5063-9240. To rack mount two instruments side-by-side, order lock-link kit 5061-9694 and flange kit 5063-9212. Be sure to use the support rails inside the rack cabinet.
34970A Refresh UG.
34970A Refresh UG.book Page 40 Wednesday, February 17, 2010 12:34 PM Front-Panel Overview This chapter introduces you to the front-panel keys and menu operation. This chapter does not give a detailed description of every front-panel key or menu operation. It does, however, give you an overview of the frontpanel menus and many front-panel operations. See chapter 4 “Features and Functions,” starting on page 87, for a complete discussion of the instrument’s capabilities and operation.
34970A Refresh UG.book Page 41 Wednesday, February 17, 2010 12:34 PM Chapter 2 Front-Panel Overview Front-Panel Menu Reference Front-Panel Menu Reference This section gives an overview of the front-panel menus. The menus are designed to automatically guide you through all parameters required to configure a particular function or operation. The remainder of this chapter contains examples of using the front-panel menus. Configure the measurement parameters on the displayed channel.
34970A Refresh UG.book Page 42 Wednesday, February 17, 2010 12:34 PM Chapter 2 Front-Panel Overview Front-Panel Menu Reference Configure the event or action that controls the scan interval. • Select the scan interval mode (interval, manual, external, or alarm). • Select the scan count. Configure the advanced measurement features on displayed channel. • • • • • • • • • Set the integration time for measurements on the displayed channel. Set the channel-to-channel delay for scanning.
34970A Refresh UG.book Page 43 Wednesday, February 17, 2010 12:34 PM Chapter 2 Front-Panel Overview Front-Panel Menu Reference Store and recall instrument states. 2 • Store up to five instrument states in non-volatile memory. • Assign a name to each storage location. • Recall stored states, power-down state, factory reset state, or preset state. Configure the remote interface (34970A). 4 • Select the GPIB address. • Configure the RS-232 interface (baud rate, parity, and flow control).
34970A Refresh UG.book Page 44 Wednesday, February 17, 2010 12:34 PM Chapter 2 Front-Panel Overview To Monitor a Single Channel To Monitor a Single Channel You can use the Monitor function to continuously take readings on a single channel, even during a scan. This feature is useful for troubleshooting your system before a test or for watching an important signal. 1 Select the channel to be monitored.
34970A Refresh UG.book Page 45 Wednesday, February 17, 2010 12:34 PM Chapter 2 Front-Panel Overview To Set a Scan Interval To Set a Scan Interval You can set the instrument’s internal timer to automatically scan at a specific interval (e.g., start a new scan sweep every 10 seconds) or when an external TTL trigger pulse is received. You can configure the instrument to scan continuously or to stop after sweeping through the scan list a specified number of times. 4 1 Select the interval scan mode.
34970A Refresh UG.book Page 46 Wednesday, February 17, 2010 12:34 PM Chapter 2 Front-Panel Overview To Apply Mx+B Scaling to Measurements To Apply Mx+B Scaling to Measurements The scaling function allows you to apply a gain and offset to all readings on a specified multiplexer channel during a scan. In addition to setting the gain (“M”) and offset (“B”) values, you can also specify a custom measurement label for your scaled readings (RPM, PSI, etc.). 1 Configure the channel.
34970A Refresh UG.book Page 47 Wednesday, February 17, 2010 12:34 PM Chapter 2 Front-Panel Overview To Configure Alarm Limits To Configure Alarm Limits The instrument has four alarms which you can configure to alert you when a reading exceeds specified limits on a channel during a scan. You can assign a high limit, a low limit, or both to any configured channel in the scan list. You can assign multiple channels to any of the four available alarms (numbered 1 through 4). 4 1 Configure the channel.
34970A Refresh UG.book Page 48 Wednesday, February 17, 2010 12:34 PM Chapter 2 Front-Panel Overview To Configure Alarm Limits 4 Set the limit value. The alarm limit values are stored in non-volatile memory for the specified channels. The default values for the high and low limits are “0”. The low limit must always be less than or equal to the high limit, even if you are using only one of the limits. A Factory Reset clears all alarm limits and turns off all alarms.
34970A Refresh UG.book Page 49 Wednesday, February 17, 2010 12:34 PM Chapter 2 Front-Panel Overview To Read a Digital Input Port To Read a Digital Input Port The multifunction module (34907A) has two non-isolated 8-bit input/output ports which you can use for reading digital patterns. You can read the live status of the bits on the port or you can configure a scan to include a digital read. 4 1 Select the Digital Input port.
34970A Refresh UG.book Page 50 Wednesday, February 17, 2010 12:34 PM Chapter 2 Front-Panel Overview To Write to a Digital Output Port To Write to a Digital Output Port The multifunction module (34907A) has two non-isolated 8-bit input/output ports which you can use for outputting digital patterns. 1 Select the Digital Output port. Select the slot containing the multifunction module and continue turning the knob until DIN is displayed (channel 01 or 02). 2 Enter the bit pattern editor.
34970A Refresh UG.book Page 51 Wednesday, February 17, 2010 12:34 PM Chapter 2 Front-Panel Overview To Read the Totalizer Count To Read the Totalizer Count The multifunction module (34907A) has a 26-bit totalizer which can count pulses at a 100 kHz rate. You can manually read the totalizer count or you can configure a scan to read the count. 1 Select the totalizer channel. 2 4 Select the slot containing the multifunction module and continue turning the knob until TOTALIZE is displayed (channel 03).
34970A Refresh UG.book Page 52 Wednesday, February 17, 2010 12:34 PM Chapter 2 Front-Panel Overview To Output a DC Voltage To Output a DC Voltage The multifunction module (34907A) has two analog outputs capable of outputting calibrated voltages between ±12 volts. 1 Select a DAC Output channel. Select the slot containing the multifunction module and continue turning the knob until DAC is displayed (channel 04 or 05). 2 Enter the output voltage editor. +00.000 V DAC 3 Set the desired output voltage.
34970A Refresh UG.book Page 53 Wednesday, February 17, 2010 12:34 PM Chapter 2 Front-Panel Overview To Configure the Remote Interface - 34970A To Configure the Remote Interface - 34970A The 34970A is shipped with both an GPIB (IEEE-488) interface and an RS-232 interface. Only one interface can be enabled at a time. The GPIB interface is selected when the instrument is shipped from the factory. GPIB Configuration 4 1 Select the GPIB interface. GPIB / 488 2 Select the GPIB address.
34970A Refresh UG.book Page 54 Wednesday, February 17, 2010 12:34 PM Chapter 2 Front-Panel Overview To Configure the Remote Interface - 34970A RS-232 Configuration 1 Select the RS-232 interface. RS-232 2 Select the baud rate. Select one of the following: 1200, 2400, 4800, 9600, 19200, 38400, 57600 (factory setting), or 115200 baud. 19200 BAUD 3 Select the parity and number of data bits. Select one of the following: None (8 data bits, factory setting), Even (7 data bits), or Odd (7 data bits).
Chapter 2 Front-Panel Overview To Configure the Remote Interface - 34972A To Configure the Remote Interface - 34972A The instrument is shipped with both a Local Area Network (LAN) interface and a Universal Serial Bus (USB) interface. Both interfaces can be enabled at the same time and both interfaces are selected when the instrument is shipped from the factory. LAN Configuration 4 1 Select the LAN interface. LAN INTERFACE 2 Enable the LAN. This is enabled by default.
34970A Refresh UG.book Page 56 Wednesday, February 17, 2010 12:34 PM Chapter 2 Front-Panel Overview To Configure the Remote Interface - 34972A USB Configuration 1 Select the USB interface. USB INTERFACE 2 Enable or disable the USB interface. Select either USB ENABLED or USB DISABLED. USB ENABLED 3 View the USB ID String The instrument will display its USB identification (USB ID) string. This is helpful in identifying the device on the USB network.
34970A Refresh UG.book Page 57 Wednesday, February 17, 2010 12:34 PM Chapter 2 Front-Panel Overview To Store the Instrument State To Store the Instrument State You can store the instrument state in one of five non-volatile storage locations. A sixth storage location automatically holds the power-down configuration of the instrument. When power is restored, the instrument can automatically return to its state before power-down (a scan in progress before power-down will also be resumed).
34970A Refresh UG.
34970A Refresh UG.
34970A Refresh UG.book Page 60 Wednesday, February 17, 2010 12:34 PM System Overview This chapter provides an overview of a computer-based system and describes the parts of a data acquisition system. This chapter is divided into the following sections: • Data Acquisition System Overview, see below.
34970A Refresh UG.book Page 61 Wednesday, February 17, 2010 12:34 PM Chapter 3 System Overview Data Acquisition System Overview The configuration on the previous page offers the following advantages: • You can use the 34970A/34972A to perform data storage, data reduction, mathematical calculations, and conversion to engineering units. You can use the PC to provide easy configuration and data presentation.
34970A Refresh UG.book Page 62 Wednesday, February 17, 2010 12:34 PM Chapter 3 System Overview Data Acquisition System Overview Measurement Software A variety of software is available to configure your data acquisition hardware and manipulate and display your measurement data. One particularly useful feature is 34972A’s Web Interface. Simply enter the IP address of your instrument in your browser’s navigation bar to launch the Web Interface.
34970A Refresh UG.book Page 63 Wednesday, February 17, 2010 12:34 PM Chapter 3 System Overview Data Acquisition System Overview Data Logging and Monitoring Agilent BenchLink Data Logger 3, which is included with your 34970A/ 34972A is a Windows®-based application that makes it easy to use the instrument with your PC for gathering and analyzing measurements. Use this software to set up your test, acquire and archive measurement data, and perform real-time display and analysis of your measurements.
34970A Refresh UG.book Page 64 Wednesday, February 17, 2010 12:34 PM Chapter 3 System Overview Data Acquisition System Overview The 34970A/34972A Data Acquisition/Switch Unit As shown below, the logic circuitry for the 34970A/34972A is divided into two sections: earth-referenced and floating. These two sections are isolated from each other in order to maintain measurement accuracy and repeatability (for more information on ground loops, see page 263).
34970A Refresh UG.book Page 65 Wednesday, February 17, 2010 12:34 PM Chapter 3 System Overview Data Acquisition System Overview The floating section contains the main system processor and controls all of the basic functionality of the instrument. This is where the instrument communicates with the plug-in modules, scans the keyboard, controls the front-panel display, and controls the internal DMM.
34970A Refresh UG.book Page 66 Wednesday, February 17, 2010 12:34 PM Chapter 3 System Overview Data Acquisition System Overview Model Number Module Name Common Uses Measurement Input 34901A 20-Channel Mux with T/C Compensation Scanning and direct measurement of temperature, voltage, resistance, frequency, and current (34901A only) using the internal DMM.
34970A Refresh UG.book Page 67 Wednesday, February 17, 2010 12:34 PM Chapter 3 System Overview Data Acquisition System Overview System Cabling The plug-in modules have screw-terminal connectors to make it easy to connect your system cabling. The type of cabling that you use to connect your signals, transducers, and sensors to the module is critical to measurement success.
34970A Refresh UG.book Page 68 Wednesday, February 17, 2010 12:34 PM Chapter 3 System Overview Data Acquisition System Overview Transducers and Sensors Transducers and sensors convert a physical quantity into an electrical quantity. The electrical quantity is measured and the result is then converted to engineering units. For example, when measuring a thermocouple, the instrument measures a DC voltage and mathematically converts it to a corresponding temperature in °C, °F, or K.
34970A Refresh UG.book Page 69 Wednesday, February 17, 2010 12:34 PM Chapter 3 System Overview Data Acquisition System Overview Alarm Limits The 34970A/34972A has four alarm outputs which you can configure to alert you when a reading exceeds specified limits on a channel during a scan. You can assign a high limit, a low limit, or both to any configured channel in the scan list. You can assign multiple channels to any of the four available alarms (numbered 1 through 4).
34970A Refresh UG.book Page 70 Wednesday, February 17, 2010 12:34 PM Chapter 3 System Overview Signal Routing and Switching Signal Routing and Switching The switching capabilities of the plug-in modules available with the 34970A/34972A provide test system flexibility and expandability. You can use the switching plug-in modules to route signals to and from your test system or multiplex signals to the internal DMM or external instruments.
34970A Refresh UG.book Page 71 Wednesday, February 17, 2010 12:34 PM Chapter 3 System Overview Signal Routing and Switching Multiplexer Switching Multiplexers allow you to connect one of multiple channels to a common channel, one at a time. A simple 4-to-1 multiplexer is shown below. When you combine a multiplexer with a measurement device, like the internal DMM, you create a scanner. For more information on scanning, see page 77.
34970A Refresh UG.book Page 72 Wednesday, February 17, 2010 12:34 PM Chapter 3 System Overview Signal Routing and Switching Matrix Switching A matrix switch connects multiple inputs to multiple outputs and therefore offers more switching flexibility than a multiplexer. Use a matrix for switching low-frequency (less than 10 MHz) signals only. A matrix is arranged in rows and columns. For example, a simple 3x3 matrix could be used to connect three sources to three test points as shown below.
34970A Refresh UG.book Page 73 Wednesday, February 17, 2010 12:34 PM Chapter 3 System Overview Signal Routing and Switching Form C (SPDT) Switching The 34903A Actuator contains 20 Form C switches (also called single-pole, double-throw). You can use Form C switches to route signals but they are typically used to control external devices.
34970A Refresh UG.book Page 74 Wednesday, February 17, 2010 12:34 PM Chapter 3 System Overview Measurement Input Measurement Input The 34970A/34972A allows you to combine a DMM (either internal or external) with multiplexer channels to create a scan. During a scan, the instrument connects the DMM to the configured multiplexer channels one at a time and makes a measurement on each channel. Any channel that can be “read” by the instrument can also be included in a scan.
34970A Refresh UG.book Page 75 Wednesday, February 17, 2010 12:34 PM Chapter 3 System Overview Measurement Input The internal DMM provides a universal input front-end for measuring a variety of transducer types without the need for additional external signal conditioning. The internal DMM includes signal conditioning, amplification (or attenuation), and a high resolution (up to 22 bits) analog-to-digital converter. A simplified diagram of the internal DMM is shown below.
34970A Refresh UG.book Page 76 Wednesday, February 17, 2010 12:34 PM Chapter 3 System Overview Measurement Input Signal Conditioning, Ranging, and Amplification Analog input signals are multiplexed into the internal DMM’s signal-conditioning section – typically comprising switching, ranging, and amplification circuitry. If the input signal is a DC voltage, the signal conditioner is composed of an attenuator for the higher input voltages and a DC amplifier for the lower input voltages.
34970A Refresh UG.book Page 77 Wednesday, February 17, 2010 12:34 PM Chapter 3 System Overview Measurement Input Main Processor The main processor, located in the floating logic section, controls the input signal conditioning, ranging, and the ADC. The main processor accepts commands from, and sends measurement results to, the earth-referenced logic section. The main processor synchronizes measurements during scanning and control operations.
34970A Refresh UG.book Page 78 Wednesday, February 17, 2010 12:34 PM Chapter 3 System Overview Measurement Input You can configure the event or action that controls the onset of each sweep through the scan list (a sweep is one pass through the scan list): • You can set the instrument’s internal timer to automatically scan at a specific interval as shown below. You can also program a time delay between channels in the scan list.
34970A Refresh UG.book Page 79 Wednesday, February 17, 2010 12:34 PM Chapter 3 System Overview Measurement Input Scanning with External Instruments If your application doesn’t require the built-in measurement capabilities of the 34970A/34972A, you can order it without the internal DMM. In this configuration, you can use the 34970A/34972A for signal routing or control applications. If you install a multiplexer plug-in module, you can use the 34970A/34972A for scanning with an external instrument.
34970A Refresh UG.book Page 80 Wednesday, February 17, 2010 12:34 PM Chapter 3 System Overview Measurement Input To control scanning with an external instrument, two control lines are provided. When the 34970A/34972A and the external instrument are properly configured, you can synchronize a scan sequence between the two.
34970A Refresh UG.book Page 81 Wednesday, February 17, 2010 12:34 PM Chapter 3 System Overview Measurement Input The Multifunction Module The multifunction module (34907A) adds two additional measurement input capabilities to the system: digital input and event totalize. The multifunction module also contains a dual voltage output (DAC) which is described in more detail on page 68.
34970A Refresh UG.book Page 82 Wednesday, February 17, 2010 12:34 PM Chapter 3 System Overview Measurement Input Totalizer The multifunction module has a 26-bit totalizer which can count pulses at a 100 kHz rate. You can manually read the totalizer count or you can configure a scan to read the count. +IN 26 Bits Totalize -IN Channel 03 Gate Gate • You can configure the totalizer to count on the rising edge or falling edge of the input signal. • The maximum count is 67,108,863 (226- 1).
34970A Refresh UG.book Page 83 Wednesday, February 17, 2010 12:34 PM Chapter 3 System Overview Control Output Control Output In addition to signal routing and measurement, you can also use the 34970A/34972A to provide simple control outputs. For example, you can control external high-power relays using the actuator module or a digital output channel.
34970A Refresh UG.book Page 84 Wednesday, February 17, 2010 12:34 PM Chapter 3 System Overview Control Output Voltage (DAC) Output The multifunction module has two analog outputs capable of outputting calibrated voltages between ±12 volts with 16 bits of resolution. Each DAC (Digital-to-Analog Converter) channel can be used as a programmable voltage source for analog input control of other devices. A simplified diagram is shown below.
34970A Refresh UG.book Page 85 Wednesday, February 17, 2010 12:34 PM Chapter 3 System Overview Control Output The Actuator / General Purpose Switch You can think of the 34903A Actuator as a control output because it is often used to control external power devices. The actuator provides 20 independent, isolated Form C (SPDT) switches.
34970A Refresh UG.book Page 86 Wednesday, February 17, 2010 12:34 PM Chapter 3 System Overview Control Output For control applications, the actuator has the following advantages: • Higher voltage and power rating than the digital output channels. The actuator switches can also be used to control power devices.
34970A Refresh UG.
34970A Refresh UG.book Page 88 Wednesday, February 17, 2010 12:34 PM Features and Functions You will find that this chapter makes it easy to look up all the details about a particular feature of the 34970A/34972A. Whether you are operating the instrument from the front panel or over the remote interface, this chapter will be useful.
34970A Refresh UG.book Page 89 Wednesday, February 17, 2010 12:34 PM Chapter 4 Features and Functions SCPI Language Conventions SCPI Language Conventions Throughout this manual, the following conventions are used for SCPI command syntax for remote interface programming: • Square brackets ( [ ] ) indicate optional keywords or parameters. • Braces ( { } ) enclose parameter choices within a command string.
34970A Refresh UG.book Page 90 Wednesday, February 17, 2010 12:34 PM Chapter 4 Features and Functions Scanning Scanning The instrument allows you to combine a DMM (either internal or external) with multiplexer channels to create a scan. During a scan, the instrument connects the DMM to the configured multiplexer channels one at a time and makes a measurement on each channel. Any channel that can be “read” by the instrument can also be included in a scan.
34970A Refresh UG.book Page 91 Wednesday, February 17, 2010 12:34 PM Chapter 4 Features and Functions Scanning • You can store up to 50,000 readings in non-volatile memory during a scan. Readings are stored only during a scan and all readings are automatically time stamped. If memory overflows (the MEM annunciator will turn on), a status register bit is set and new readings will overwrite the first readings stored (the most recent readings are always preserved).
34970A Refresh UG.book Page 92 Wednesday, February 17, 2010 12:34 PM Chapter 4 Features and Functions Scanning • While a scan is running, you can perform some low-level control operations on modules that do not contain channels in the scan list. For example, you can open or close channels or issue a Card Reset on switching modules that do not contain channels in the scan list.
34970A Refresh UG.book Page 93 Wednesday, February 17, 2010 12:34 PM Chapter 4 Features and Functions Scanning Power Failure • When shipped from the factory, the instrument is configured to automatically recall the power-down state when power is restored. In this configuration, the instrument will automatically recall the instrument state at power-down and resume a scan in progress.
34970A Refresh UG.book Page 94 Wednesday, February 17, 2010 12:34 PM Chapter 4 Features and Functions Scanning Adding Channels to a Scan List Before you can initiate a scan, you must configure the channels to be scanned and set up a scan list (these two operations occur simultaneously from the front panel). The instrument automatically scans the configured channels in ascending order from slot 100 through slot 300. To Build a Scan List From the Front Panel: .
34970A Refresh UG.book Page 95 Wednesday, February 17, 2010 12:34 PM Chapter 4 Features and Functions Scanning To Build a Scan List From the Remote Interface: • • The MEASure?, CONFigure, and ROUTe:SCAN commands contain a scan_list parameter which defines the list of channels in the scan list. Note that each time you send one of these commands, it redefines the scan list. To determine which channels are currently in the scan list, you can send the ROUTe:SCAN? query command.
34970A Refresh UG.book Page 96 Wednesday, February 17, 2010 12:34 PM Chapter 4 Features and Functions Scanning Scan Interval You can configure the event or action that controls the onset of each sweep through the scan list (a sweep is one pass through the scan list): • You can set the instrument’s internal timer to automatically scan at a specific interval. You can also program a time delay between channels in the scan list. • You can manually control a scan by repeatedly pressing front panel.
34970A Refresh UG.book Page 97 Wednesday, February 17, 2010 12:34 PM Chapter 4 Features and Functions Scanning • You can set the scan interval to any value between 0 seconds and 99:59:59 hours (359,999 seconds), with 1 ms resolution. • Once you have initiated the scan, the instrument will continue scanning until you stop it or until the scan count is reached. See “Scan Count” on page 102 for more information.
34970A Refresh UG.book Page 98 Wednesday, February 17, 2010 12:34 PM Chapter 4 Features and Functions Scanning Scan Once In this configuration, the instrument waits for either a front-panel key press or a remote interface command before sweeping through the scan list. • All readings from the scan are stored in non-volatile memory. Readings accumulate in memory until the scan is terminated (until the scan count is reached or until you abort the scan).
34970A Refresh UG.book Page 99 Wednesday, February 17, 2010 12:34 PM Chapter 4 Features and Functions Scanning External Scanning In this configuration, the instrument sweeps through the scan list once each time a low-going TTL pulse is received on the rear-panel Ext Trig Input line (pin 6). 5V Input 0V Ext Trig Input Gnd > 1 s Ext Trig Connector • You can specify a scan count which sets the number of external pulses the instrument will accept before terminating the scan.
34970A Refresh UG.book Page 100 Wednesday, February 17, 2010 12:34 PM Chapter 4 Features and Functions Scanning • Remote Interface Operation: The following program segment configures the instrument for an External Scan. TRIG:SOURCE EXT TRIG:COUNT 2 INIT Select the external trigger configuration Sweep the scan list 2 times Initiate the scan Note: To stop a scan, send the ABORt command.
34970A Refresh UG.book Page 101 Wednesday, February 17, 2010 12:34 PM Chapter 4 Features and Functions Scanning • Front-Panel Operation: SCAN ON ALARM To enable the Monitor function select the desired channel and then press . To initiate the scan, press . When an alarm event occurs, the scan starts and readings are stored in memory. Note: To stop a scan, press and hold . • Remote Interface Operation: The following program segment configures the instrument to scan when an alarm occurs.
34970A Refresh UG.book Page 102 Wednesday, February 17, 2010 12:34 PM Chapter 4 Features and Functions Scanning Scan Count You can specify the number of times the instrument will sweep through the scan list. When the specified number of sweeps have occurred, the scan stops. • Select a scan count between 1 to 50,000 scan sweeps, or continuous.
34970A Refresh UG.book Page 103 Wednesday, February 17, 2010 12:34 PM Chapter 4 Features and Functions Scanning • Front-Panel Operation: 00020 SCANS The default is CONTINUOUS. To set the count to a value between 1 and 50,000 scans, turn the knob clockwise and enter a number. • Remote Interface Operation: TRIG:COUNT 20 Note: To configure a continuous scan, send TRIG:COUNT INFINITY.
34970A Refresh UG.book Page 104 Wednesday, February 17, 2010 12:34 PM Chapter 4 Features and Functions Scanning Reading Format During a scan, the instrument automatically adds a time stamp to all readings and stores them in non-volatile memory. Each reading is stored with measurement units, time stamp, channel number, and alarm status information.
34970A Refresh UG.book Page 105 Wednesday, February 17, 2010 12:34 PM Chapter 4 Features and Functions Scanning Channel Delay You can control the pace of a scan sweep by inserting a delay between multiplexer channels in the scan list (useful for high-impedance or highcapacitance circuits). The delay is inserted between the relay closure and the actual measurement on the channel. The programmed channel delay overrides the default channel delay that the instrument automatically adds to each channel.
34970A Refresh UG.book Page 106 Wednesday, February 17, 2010 12:34 PM Chapter 4 Features and Functions Scanning Automatic Channel Delays If you do not specify a channel delay, the instrument selects a delay for you. The delay is determined by function, range, integration time, and AC filter setting as shown below. DC Voltage, Thermocouple, DC Current (for all ranges): Integration Time Channel Delay PLC >1 PLC 2.0 ms 1.
34970A Refresh UG.book Page 107 Wednesday, February 17, 2010 12:34 PM Chapter 4 Features and Functions Scanning • Front-Panel Operation: CH DELAY AUTO • Remote Interface Operation: The following command enables an automatic channel delay on channel 01. ROUT:CHAN:DELAY:AUTO ON,(@101) Selecting a specific channel delay using the ROUTe:CHANnel:DELay command disables the automatic channel delay.
34970A Refresh UG.book Page 108 Wednesday, February 17, 2010 12:34 PM Chapter 4 Features and Functions Scanning • While a scan is running, the instrument automatically stores the minimum and maximum readings and calculates the average for each channel. You can read these values at any time, even during a scan. • Each reading is stored with measurement units, time stamp, channel number, and alarm status information.
34970A Refresh UG.book Page 109 Wednesday, February 17, 2010 12:34 PM Chapter 4 Features and Functions Scanning • Front-Panel Operation: From the front panel, data is available for the last 100 readings on each channel readings taken during a scan (all of the data is available from the remote interface).
34970A Refresh UG.book Page 110 Wednesday, February 17, 2010 12:34 PM Chapter 4 Features and Functions Scanning • Remote Interface Operation: The following command retrieves stored readings from memory (the readings are not erased). FETCH? Use the following commands to query the statistics on the readings stored in memory for a specific channel. These commands do not remove the data from memory.
34970A Refresh UG.book Page 111 Wednesday, February 17, 2010 12:34 PM Chapter 4 Features and Functions Scanning with External Instruments Scanning with External Instruments If your application doesn’t require the built-in measurement capabilities of the 34970A/34972A, you can order it without the internal DMM. In this configuration, you can use the 34970A/34972A for signal routing or control applications.
34970A Refresh UG.book Page 112 Wednesday, February 17, 2010 12:34 PM Chapter 4 Features and Functions Scanning with External Instruments To control scanning with an external instrument, two control lines are provided. When the 34970A/34972A and the external instrument are properly configured, you can synchronize a scan sequence between the two.
34970A Refresh UG.book Page 113 Wednesday, February 17, 2010 12:34 PM Chapter 4 Features and Functions Scanning with External Instruments • You can configure the event or action that controls the onset of each sweep through the scan list (a sweep is one pass through the scan list). When the internal DMM is removed (or disabled), the default scan interval source is “timer.” For more information, refer to “Scan Interval” on page 80.
34970A Refresh UG.book Page 114 Wednesday, February 17, 2010 12:34 PM Chapter 4 Features and Functions Scanning with External Instruments • Remote Interface Operation: The following program segment configures the instrument for an externally controlled scan.
34970A Refresh UG.book Page 115 Wednesday, February 17, 2010 12:34 PM Chapter 4 Features and Functions General Measurement Configuration General Measurement Configuration This section contains general information to help you configure the instrument for making measurements during a scan. Since these parameters are used by several measurement functions, the discussion is combined into one common section.
34970A Refresh UG.book Page 116 Wednesday, February 17, 2010 12:34 PM Chapter 4 Features and Functions General Measurement Configuration • For frequency and period measurements, the "range" parameter is used to compute a specific measurement resolution (see the Agilent 34970A/34972A Programmer’s Reference Help for details). When specifying a (non-default) resolution, both the range and resolution parameters must be specified within the MEASure? and CONFigure commands.
34970A Refresh UG.book Page 117 Wednesday, February 17, 2010 12:34 PM Chapter 4 Features and Functions General Measurement Configuration Measurement Resolution Resolution is expressed in terms of number of digits the instrument can measure or display on the front panel. You can set the resolution to 4, 5, or 6 full digits, plus a “½” digit which can only be a “0” or “1”. To increase your measurement accuracy and improve noise rejection, select 6½ digits.
34970A Refresh UG.book Page 118 Wednesday, February 17, 2010 12:34 PM Chapter 4 Features and Functions General Measurement Configuration • The specified resolution is used for all measurements on the selected channel. If you have applied Mx+B scaling or have assigned alarms to the selected channel, those measurements are also made using the specified resolution. Measurements taken during the Monitor function also use the specified resolution.
34970A Refresh UG.book Page 119 Wednesday, February 17, 2010 12:34 PM Chapter 4 Features and Functions General Measurement Configuration • Remote Interface Operation: Specify the resolution in the same units as the measurement function, not in number of digits. For example, if the function is DC volts, specify the resolution in volts. For frequency, specify the resolution in hertz. You can select the resolution using parameters in the MEASure? and CONFigure commands.
34970A Refresh UG.book Page 120 Wednesday, February 17, 2010 12:34 PM Chapter 4 Features and Functions General Measurement Configuration Custom A/D Integration Time Integration time is the period of time that the instrument’s analog-to-digital (A/D) converter samples the input signal for a measurement. Integration time affects the measurement resolution (for better resolution, use a longer integration time) and measurement speed (for faster measurements, use a shorter integration time).
34970A Refresh UG.book Page 121 Wednesday, February 17, 2010 12:34 PM Chapter 4 Features and Functions General Measurement Configuration • The instrument selects 1 PLC when the measurement function is changed and after a Factory Reset (*RST command). An Instrument Preset (SYSTem:PRESet command) or Card Reset (SYSTem:CPON command) does not change the integration time setting. • Front-Panel Operation: First, select the measurement function on the active channel.
34970A Refresh UG.book Page 122 Wednesday, February 17, 2010 12:34 PM Chapter 4 Features and Functions General Measurement Configuration Autozero When autozero is enabled (default), the instrument internally disconnects the input signal following each measurement, and takes a zero reading. It then subtracts the zero reading from the preceding reading. This prevents offset voltages present on the instrument’s input circuitry from affecting measurement accuracy.
34970A Refresh UG.book Page 123 Wednesday, February 17, 2010 12:34 PM Chapter 4 Features and Functions Temperature Measurement Configuration Temperature Measurement Configuration This section contains information to help you configure the instrument for making temperature measurements. For more information on the types of temperature transducers, see “Temperature Measurements” starting on page 267. The instrument supports direct measurement of thermocouples, RTDs, and thermistors.
34970A Refresh UG.book Page 124 Wednesday, February 17, 2010 12:34 PM Chapter 4 Features and Functions Temperature Measurement Configuration Thermocouple Measurements To connect a thermocouple to the module’s screw terminals, see page 28. • The instrument supports the following thermocouple types: B, E, J, K, N, R, S, and T using ITS-90 software conversions. The default is a J-Type thermocouple. • Thermocouple measurements require a reference junction temperature.
34970A Refresh UG.book Page 125 Wednesday, February 17, 2010 12:34 PM Chapter 4 Features and Functions Temperature Measurement Configuration • The thermocouple check feature allows you to verify that your thermocouples are properly connected to the screw terminals for measurements. If you enable this feature, the instrument measures the channel resistance after each thermocouple measurement to ensure a proper connection.
34970A Refresh UG.book Page 126 Wednesday, February 17, 2010 12:34 PM Chapter 4 Features and Functions Temperature Measurement Configuration • Remote Interface Operation: You can use the MEASure? or CONFigure command to select the probe type and thermocouple type. For example, the following statement configures channel 301 for a Jtype thermocouple measurement. CONF:TEMP TC,J,(@301) You can also use the SENSe command to select the probe type and thermocouple type.
34970A Refresh UG.book Page 127 Wednesday, February 17, 2010 12:34 PM Chapter 4 Features and Functions Temperature Measurement Configuration RTD Measurements To connect an RTD to the module’s screw terminals, see page 28. • The instrument supports RTDs with = 0.00385 (DIN / IEC 751) using ITS-90 software conversions or = 0.00391 using IPTS-68 software conversions. The default is = 0.00385. • The resistance of an RTD is nominal at 0 °C and is referred to as R0.
34970A Refresh UG.book Page 128 Wednesday, February 17, 2010 12:34 PM Chapter 4 Features and Functions Temperature Measurement Configuration • Remote Interface Operation: You can use the MEASure? or CONFigure command to select the probe type and RTD type. For example, the following statement configures channel 301 for 2-wire measurements of an RTD with = 0.00385 (use “85” to specify = 0.00385 or “91” to specify = 0.00391).
34970A Refresh UG.book Page 129 Wednesday, February 17, 2010 12:34 PM Chapter 4 Features and Functions Temperature Measurement Configuration Thermistor Measurements To connect a thermistor to the module’s screw terminals, see page 28. • The instrument supports 2.2 k (44004), 5 k (44007), and 10 k (44006) thermistors. • Front-Panel Operation: To select the thermistor function for the active channel, choose the following items.
34970A Refresh UG.book Page 130 Wednesday, February 17, 2010 12:34 PM Chapter 4 Features and Functions Voltage Measurement Configuration Voltage Measurement Configuration To connect voltage sources to the module’s screw terminals, see page 28. This section contains information to help you configure the instrument for making voltage measurements. The instrument can measure DC and true RMS ac-coupled voltages on the measurement ranges shown below.
34970A Refresh UG.book Page 131 Wednesday, February 17, 2010 12:34 PM Chapter 4 Features and Functions Voltage Measurement Configuration • Remote Interface Operation: You can enable or disable the automatic input resistance mode on the specified channels. With AUTO OFF (default), the input resistance is fixed at 10 M for all ranges. With AUTO ON, the input resistance is set to >10 G for the three lowest DC voltage ranges. The MEASure? and CONFigure commands automatically select AUTO OFF.
34970A Refresh UG.book Page 132 Wednesday, February 17, 2010 12:34 PM Chapter 4 Features and Functions Resistance Measurement Configuration Resistance Measurement Configuration To connect resistances to the module’s screw terminals, see page 28. This section contains information to help you configure the instrument for making resistance measurements. Use the 2-wire method for ease of wiring and higher density or the 4-wire method for improved measurement accuracy. The measurement ranges are shown below.
34970A Refresh UG.book Page 133 Wednesday, February 17, 2010 12:34 PM Chapter 4 Features and Functions Current Measurement Configuration Current Measurement Configuration To connect a current source to the module’s screw terminals, see page 28. This section contains information to help you configure the instrument for making current measurements on the 34901A multiplexer module. This module has two fused channels for direct DC and AC current measurements on the measurement ranges shown below.
34970A Refresh UG.book Page 134 Wednesday, February 17, 2010 12:34 PM Chapter 4 Features and Functions Current Measurement Configuration • Front-Panel Operation: First, select the AC current (or AC voltage) function on the active channel. Then, go to the Advanced menu and select the slow filter (3 Hz), medium filter (20 Hz), or fast filter (200 Hz) for the active channel. The default is the medium filter.
34970A Refresh UG.book Page 135 Wednesday, February 17, 2010 12:34 PM Chapter 4 Features and Functions Frequency Measurement Configuration Frequency Measurement Configuration To connect an AC source to the module’s screw terminals, see page 28. Low Frequency Timeout The instrument uses three different timeout ranges for frequency measurements. The instrument selects a slow, medium, or fast timeout based on the input frequency that you specify for the selected channels.
34970A Refresh UG.book Page 136 Wednesday, February 17, 2010 12:34 PM Chapter 4 Features and Functions Mx+B Scaling Mx+B Scaling The scaling function allows you to apply a gain and offset to all readings on a specified multiplexer channel during a scan. In addition to setting the gain (“M”) and offset (“B”) values, you can also specify a custom measurement label for your scaled readings (RPM, PSI, etc.). You can apply scaling to any multiplexer channels and for any measurement function.
34970A Refresh UG.book Page 137 Wednesday, February 17, 2010 12:34 PM Chapter 4 Features and Functions Mx+B Scaling • You can make a null measurement on a channel and store it as the offset (“B”) for subsequent measurements. This allows you to adjust for voltage or resistive offsets through your wiring to the point of the measurement. • During a Monitor operation, the gain and offset values are applied to all readings on the specified channel. • You can specify a custom label with up to three characters.
34970A Refresh UG.book Page 138 Wednesday, February 17, 2010 12:34 PM Chapter 4 Features and Functions Mx+B Scaling • The maximum gain allowed is ±1E+15 and the maximum offset allowed is ±1E+15. • The MEASure? and CONFigure commands automatically set the gain (“M”) to 1 and offset (“B”) to 0. • A Factory Reset (*RST command) turns off scaling and clears the scaling values on all channels.
34970A Refresh UG.book Page 139 Wednesday, February 17, 2010 12:34 PM Chapter 4 Features and Functions Alarm Limits Alarm Limits The instrument has four alarms which you can configure to alert you when a reading exceeds specified limits on a channel during a scan. You can assign a high limit, a low limit, or both to any configured channel in the scan list. You can assign multiple channels to any of the four available alarms (numbered 1 through 4).
34970A Refresh UG.book Page 140 Wednesday, February 17, 2010 12:34 PM Chapter 4 Features and Functions Alarm Limits • You can assign an alarm to any configured channel and multiple channels can be assigned to the same alarm number. However, you cannot assign alarms on a specific channel to more than one alarm number. • When an alarm occurs, the instrument stores relevant information about the alarm in the queue.
34970A Refresh UG.book Page 141 Wednesday, February 17, 2010 12:34 PM Chapter 4 Features and Functions Alarm Limits • Alarms are logged in the alarm queue only when a reading crosses a limit, not while it remains outside the limit and not when it returns to within limits. Alarm Event No Alarm Upper Limit Lower Limit • Four TTL alarm outputs are available on the rear-panel Alarms connector.
34970A Refresh UG.book Page 142 Wednesday, February 17, 2010 12:34 PM Chapter 4 Features and Functions Alarm Limits • In addition to being stored in reading memory, alarms are also recorded in their own SCPI status system. You can configure the instrument to use the status system to generate a Service Request (SRQ) when alarms are generated. See the Agilent 34970A/34972A Programmer’s Reference Help for more information. • The default values for the upper and lower alarm limits are “0”.
34970A Refresh UG.book Page 143 Wednesday, February 17, 2010 12:34 PM Chapter 4 Features and Functions Alarm Limits • To set the upper and lower alarm limits on the specified channels, use the following commands. CALC:LIMIT:UPPER 5.25,(@103,212) CALC:LIMIT:LOWER 0.025,(@103,212) • To enable the upper and lower alarm limits on the specified channels, use the following commands.
34970A Refresh UG.book Page 144 Wednesday, February 17, 2010 12:34 PM Chapter 4 Features and Functions Alarm Limits • Remote Interface Operation: The following command reads data from the alarm queue (one alarm event is read and cleared each time this command is executed). SYSTEM:ALARM? The following is an example of an alarm stored in the alarm queue (if no alarm data is in the queue, the command returns “0” for each field). . 1 Reading with Units (31.009 °C) 2 Date (May 1, 1997) 3 Time (2:39:40.
34970A Refresh UG.book Page 145 Wednesday, February 17, 2010 12:34 PM Chapter 4 Features and Functions Alarm Limits Using the Alarm Output Lines Four TTL alarm outputs are available on the rear-panel Alarms connector. You can use these hardware outputs to trigger external alarm lights, sirens, or send a TTL pulse to your control system. You can assign an alarm to any configured channel and multiple channels can be assigned to the same alarm number.
34970A Refresh UG.book Page 146 Wednesday, February 17, 2010 12:34 PM Chapter 4 Features and Functions Alarm Limits • Track Mode: In this mode, the corresponding output line is asserted only when a reading crosses a limit and remains outside the limit. When a reading returns to within limits, the output line is automatically cleared. You can manually clear the output lines at any time (even during a scan) and the alarm data in memory is not cleared (however, data is cleared when you initiate a new scan).
34970A Refresh UG.book Page 147 Wednesday, February 17, 2010 12:34 PM Chapter 4 Features and Functions Alarm Limits • Remote Interface Operation: To clear the specified output lines (or to clear all four lines), use one of the following commands. OUTPUT:ALARM2:CLEAR OUTPUT:ALARM:CLEAR:ALL Clear alarm output line 2 Clear all four alarm outputs To select the output configuration for all four output lines, use the following command.
34970A Refresh UG.book Page 148 Wednesday, February 17, 2010 12:34 PM Chapter 4 Features and Functions Alarm Limits Using Alarms With the Multifunction Module You can configure the instrument to generate an alarm when a specific bit pattern or bit pattern change is detected on a digital input channel or when a specific count is reached on a totalizer channel. These channels do not have to be part of the scan list to generate an alarm. Alarms are evaluated continuously as soon as you enable them.
34970A Refresh UG.book Page 149 Wednesday, February 17, 2010 12:34 PM Chapter 4 Features and Functions Alarm Limits • Remote Interface Operation (Digital Input Channel): To assign the alarm number to report any alarm conditions on the specified digital input channels, use the following command. OUTPut:ALARm[1|2|3|4]:SOURce (@) To configure alarms on the specified digital input channel, use the following commands (also see the example on the following page).
34970A Refresh UG.book Page 150 Wednesday, February 17, 2010 12:34 PM Chapter 4 Features and Functions Alarm Limits Example: Configuring an Alarm on a Digital Input Assume that you want to generate an alarm when a binary pattern of “1000” is read on the upper four bits of port 1. Send the following commands to configure the port for an alarm.
34970A Refresh UG.book Page 151 Wednesday, February 17, 2010 12:34 PM Chapter 4 Features and Functions Digital Input Operations Digital Input Operations The multifunction module (34907A) has two non-isolated 8-bit input/ output ports which you can use for reading digital patterns. You can read the live status of the bits on the port or you can configure a scan to include a digital read. • The digital input channels are numbered “s01” (lower byte) and “s02” (upper byte), where s represents the slot number.
34970A Refresh UG.book Page 152 Wednesday, February 17, 2010 12:34 PM Chapter 4 Features and Functions Digital Input Operations • A Factory Reset (*RST command), Instrument Preset (SYSTem:PRESet command), and Card Reset (SYSTem:CPON command) from the remote interface will reconfigure both ports as input ports. Note that a from the front panel resets only the port currently selected (both ports are not reset).
34970A Refresh UG.book Page 153 Wednesday, February 17, 2010 12:34 PM Chapter 4 Features and Functions Totalizer Operations Totalizer Operations The multifunction module has a 26-bit totalizer which can count TTL pulses at a 100 kHz rate. You can manually read the totalizer count or you can configure a scan to read the count. • The totalizer channel is numbered “s03”, where s represents the slot number. • You can configure the instrument to count on the rising edge or falling edge of the input signal.
34970A Refresh UG.book Page 154 Wednesday, February 17, 2010 12:34 PM Chapter 4 Features and Functions Totalizer Operations • Using the hardware jumper labeled “Totalize Threshold” on the module, you can control the threshold at which an edge is detected. Move the jumper to the “AC” position to detect changes through 0 volts. Move the jumper to the “TTL” position (factory setting) to detect changes through TTL threshold levels. 0 V Threshold (AC) 2.
34970A Refresh UG.book Page 155 Wednesday, February 17, 2010 12:34 PM Chapter 4 Features and Functions Totalizer Operations • Front-Panel Operation: After selecting the totalizer, press to read the count. If you have selected the READ+ RESET mode, the count is reset each time it is read. The count is displayed until you press another key, turn the knob, or until the display times out. To configure the totalizer reset mode, choose from the following items.
34970A Refresh UG.book Page 156 Wednesday, February 17, 2010 12:34 PM Chapter 4 Features and Functions Totalizer Operations • Remote Interface Operation: To read the count from the specified totalizer channel, send the following command. The count may be returned with time stamp, channel number, and alarm status information depending on the FORMat:READing command setting (see “Reading Format” on page 104 for more information).
34970A Refresh UG.book Page 157 Wednesday, February 17, 2010 12:34 PM Chapter 4 Features and Functions Digital Output Operations Digital Output Operations The multifunction module (34907A) has two non-isolated 8-bit input/ output ports which you can use for outputting digital patterns. • The digital output channels are numbered “s01” (lower byte) and “s02” (upper byte), where s represents the slot number.
34970A Refresh UG.book Page 158 Wednesday, February 17, 2010 12:34 PM Chapter 4 Features and Functions Digital Output Operations • Remote Interface Operation: From the remote interface, you can output an 8-bit byte to one port or a 16-bit word to both ports simultaneously using the following commands. You must specify a decimal value (binary data is not accepted). If you are going to read both ports simultaneously, you must send the command to port 01.
34970A Refresh UG.book Page 159 Wednesday, February 17, 2010 12:34 PM Chapter 4 Features and Functions DAC Output Operations DAC Output Operations The multifunction module (34907A) has two low-noise analog outputs capable of outputting calibrated voltages between ±12 volts with 16 bits of resolution. Each DAC (Digital-to-Analog Converter) channel can be used as a programmable voltage source for analog input control of other devices.
34970A Refresh UG.book Page 160 Wednesday, February 17, 2010 12:34 PM Chapter 4 Features and Functions System-Related Operations System-Related Operations This section gives information on system-related topics such as storing instrument states, reading errors, running a self-test, displaying messages on the front panel, setting the system clock, disabling the internal DMM, reading the firmware revisions, and reading the relay cycle count.
34970A Refresh UG.book Page 161 Wednesday, February 17, 2010 12:34 PM Chapter 4 Features and Functions System-Related Operations • You can assign a name to the storage locations (you cannot assign a name to location “0”). You can name a location from the front panel or over the remote interface but you can only recall a named state from the front panel. From the remote interface, you can only recall a stored state using a number (0 through 5). • The name can contain up to 12 characters.
34970A Refresh UG.book Page 162 Wednesday, February 17, 2010 12:34 PM Chapter 4 Features and Functions System-Related Operations To assign a name to a stored state to be recalled from the front panel, send the following command. From the remote interface, you can only recall a stored state using a number (0 through 5). MEM:STATE:NAME 1,TEST_RACK_1 To configure the instrument to automatically issue a Factory Reset (*RST command) when power is restored, send the following command.
34970A Refresh UG.book Page 163 Wednesday, February 17, 2010 12:34 PM Chapter 4 Features and Functions System-Related Operations Error Conditions When the front-panel ERROR annunciator turns on, one or more command syntax or hardware errors have been detected. A record of up to 10 errors (34970A) or 20 errors (34972A) is stored in the instrument’s error queue. See chapter 6 for a complete listing of the errors. • Errors are retrieved in first-in-first-out (FIFO) order.
34970A Refresh UG.book Page 164 Wednesday, February 17, 2010 12:34 PM Chapter 4 Features and Functions System-Related Operations Self-Test A power-on self-test occurs automatically when you turn on the instrument. This limited test assures you that the instrument and all installed plug-in modules are operational. This self-test does not perform the extensive set of tests that are included as part of the complete selftest described below.
34970A Refresh UG.book Page 165 Wednesday, February 17, 2010 12:34 PM Chapter 4 Features and Functions System-Related Operations Display Control For security reasons or for a slight increase in scanning rates, you may want to turn off the front-panel display. From the remote interface, you can also display a 13-character message on the front-display. • You can only disable the front-panel display by sending a command from the remote interface (you cannot disable the front panel while in local operation).
34970A Refresh UG.book Page 166 Wednesday, February 17, 2010 12:34 PM Chapter 4 Features and Functions System-Related Operations • Remote Interface Operation: The following command turns off the front panel display. DISPLAY OFF The following command displays a message on the front panel and turns on the display if disabled. DISP:TEXT ’SCANNING ...’ To clear the message displayed on the front panel (without changing the display state), send the following command.
34970A Refresh UG.book Page 167 Wednesday, February 17, 2010 12:34 PM Chapter 4 Features and Functions System-Related Operations Internal DMM Disable You can scan through the configured channels using either the internal DMM or an external instrument. For externally-controlled scans, you must either remove the internal DMM from the instrument or • For information on controlling a scan with an external instrument, refer to “Scanning With External Instruments” on page 111.
34970A Refresh UG.book Page 168 Wednesday, February 17, 2010 12:34 PM Chapter 4 Features and Functions System-Related Operations • Front-Panel Operation: REV X.X-Y.Y-Z.Z (for 34970A) REV X.XX-Y.YY-Z (for 34972A) Turn the knob to read the firmware revision number for the module installed in each of the three slots. If a slot does not contain a module, EMPTY SLOT is displayed.
34970A Refresh UG.book Page 169 Wednesday, February 17, 2010 12:34 PM Chapter 4 Features and Functions System-Related Operations Relay Cycle Count The instrument has a Relay Maintenance System to help you predict relay end-of-life. The instrument counts the cycles on each relay in the instrument and stores the total count in non-volatile memory on each switch module. You can use this feature on any of the relay modules and the internal DMM.
34970A Refresh UG.book Page 170 Wednesday, February 17, 2010 12:34 PM Chapter 4 Features and Functions System-Related Operations • Front-Panel Operation: To read the count on the active channel, choose the following item and then turn the knob. To read the count on the internal DMM relays, turn the knob counterclockwise beyond the lowest numbered channel in the instrument. To read the “hidden” backplane and bank relays, turn the knob clockwise beyond the highest numbered channel in the current slot.
34970A Refresh UG.book Page 171 Wednesday, February 17, 2010 12:34 PM Chapter 4 Features and Functions Single-Channel Monitoring Single-Channel Monitoring In the Monitor function, the instrument takes readings as often as it can on a single channel, even during a scan. This feature is useful for troubleshooting your system before a test or for watching an important signal. Any channel that can be “read” by the instrument can be monitored.
34970A Refresh UG.book Page 172 Wednesday, February 17, 2010 12:34 PM Chapter 4 Features and Functions Single-Channel Monitoring • In the Alarm Scan configuration (see “Scanning on Alarm” on page 100), the instrument sweeps the scan list once each time a reading crosses an alarm limit on a channel. In this configuration, you may use the Monitor function to continuously take readings on a selected channel and wait for an alarm on that channel.
34970A Refresh UG.book Page 173 Wednesday, February 17, 2010 12:34 PM Chapter 4 Features and Functions Single-Channel Monitoring SCPI Language Version Query The instrument complies with the rules and conventions of the present version of SCPI (Standard Commands for Programmable Instruments). You can determine the SCPI version with which the instrument is in compliance by sending a command from the remote interface. You cannot query the SCPI version from the front panel.
34970A Refresh UG.book Page 174 Wednesday, February 17, 2010 12:34 PM Chapter 4 Features and Functions Mass Memory (USB) Subsystem - 34972A Mass Memory (USB) Subsystem - 34972A This section gives information on the mass memory subsystem (34972A only). The mass memory subsystem enables you to capture data to, or import an instrument configuration from a USB drive connected to the instrument’s USB port. General Capabilities The mass memory subsystem suppports the following capabilities: 1.
34970A Refresh UG.book Page 175 Wednesday, February 17, 2010 4:07 PM Chapter 4 Features and Functions Mass Memory (USB) Subsystem - 34972A There are two annunciators related to the USB drive: MEM (on) - Indicates that a USB drive is connected to the 34972A. MEM (flashing) - Indicates the the USB drive is either streaming data to USB (logging), copying from reading memory to USB (exporting), or importing a configuration from Agilent BenchLink Data Logger. AUTO (on) - Indicates that logging is active.
34970A Refresh UG.
34970A Refresh UG.
34970A Refresh UG.book Page 178 Wednesday, February 17, 2010 12:34 PM Chapter 4 Features and Functions Mass Memory (USB) Subsystem - 34972A For example, the folder named: /34972A/data/MY00012345/20091210_134523123 would indicate a scan on instrument number MY00012345 that started approximately 23.123 seconds after 1:45 pm (13:45) on December 10, 2009. File Descriptions The top level folder described above will contain two types of files. The first is a file named as follows: config.
34970A Refresh UG.book Page 179 Wednesday, February 17, 2010 12:34 PM Chapter 4 Features and Functions Mass Memory (USB) Subsystem - 34972A Contents of Data Files Logging into data files is only supported for channels that are in the scan list. The possible channels are shown in the table below; note that s stands for the slot number, which is 1, 2, or 3. For example, the 34901A module supports could have channels 101-120, 201-220, or 301-320.
34970A Refresh UG.book Page 180 Wednesday, February 17, 2010 12:34 PM Chapter 4 Features and Functions Mass Memory (USB) Subsystem - 34972A A sample file is shown below. Sweep # Time Chan 201 (VDC) Chan 202 (VDC) 1 01/26/2009 08:07:12:237 0.36823663 1.23895216 2 01/26/2009 08:07:13:237 0.62819233 0.98372939 3 01/26/2009 08:07:14:237 0.38238212 0.39382906 4 01/26/2009 08:07:15:237 0.46773299 0.55543345 5 01/26/2009 08:07:16:237 1.32323567 0.
34970A Refresh UG.book Page 181 Wednesday, February 17, 2010 12:34 PM Chapter 4 Features and Functions USB Drive Front Panel - 34972A USB Drive Front Panel - 34972A This section gives information on configuring the USB drive with the front panel. For more information about using the USB drive, see Mass Memory (USB) Subsystem - 34972A, on page 174.
34970A Refresh UG.book Page 182 Wednesday, February 17, 2010 12:34 PM Chapter 4 Features and Functions USB Drive Front Panel - 34972A Formatting Readings You can control how readings are formatted on the USB drive. In particular, you can choose whether the readings are stored in one large file (ROWS/FILE:AUTO) or in a series of files with 64K - 1 rows per file (ROWS/FILE:64K). You can also choose whether the files are formatted with a tab, comma or semicolon between columns.
34970A Refresh UG.book Page 183 Wednesday, February 17, 2010 12:34 PM Chapter 4 Features and Functions Remote Interface Configuration - 34970A Remote Interface Configuration - 34970A This section gives information on configuring the 34970A for remote interface communication. For more information on configuring the instrument from the front panel, see “To Configure the Remote Interface” starting on page 53.
34970A Refresh UG.book Page 184 Wednesday, February 17, 2010 12:34 PM Chapter 4 Features and Functions Remote Interface Configuration - 34970A Remote Interface Selection The 34970A is shipped with both an GPIB (IEEE-488) interface and an RS-232 interface. Only one interface can be enabled at a time. The GPIB interface is selected when the instrument is shipped from the factory.
34970A Refresh UG.book Page 185 Wednesday, February 17, 2010 12:34 PM Chapter 4 Features and Functions Remote Interface Configuration - 34970A Baud Rate Selection (RS-232) You can select one of eight baud rates for RS-232 operation. The rate is set to 57,600 baud when the instrument is shipped from the factory. You can set the baud rate from the front panel only. • Select one of the following: 1200, 2400, 4800, 9600, 19200, 38400, 57600 (factory setting), or 115200 baud.
34970A Refresh UG.book Page 186 Wednesday, February 17, 2010 12:34 PM Chapter 4 Features and Functions Remote Interface Configuration - 34970A Flow Control Selection (RS-232) You can select one of several flow control methods to coordinate the transfer of data between the instrument and your computer or modem. The method that you select will be determined by the flow method used by your computer or modem. You can select the flow control method from the front panel only.
34970A Refresh UG.book Page 187 Wednesday, February 17, 2010 12:34 PM Chapter 4 Features and Functions Remote Interface Configuration - 34970A • Modem: This mode uses the DTR/DSR and RTS/CTS lines to control the flow of data between the instrument and a modem. When the RS232 interface is selected, the instrument sets the DTR line true. The DSR line is set true when the modem is on-line. The instrument sets the RTS line true when it is ready to receive data.
34970A Refresh UG.book Page 188 Wednesday, February 17, 2010 12:34 PM Chapter 4 Features and Functions Remote Interface Configuration - 34972A Remote Interface Configuration - 34972A This section gives information on configuring the instrument for remote interface communication. For more information on configuring the instrument from the front panel, see “To Configure the Remote Interface” starting on page 53.
34970A Refresh UG.book Page 189 Wednesday, February 17, 2010 12:34 PM Chapter 4 Features and Functions Remote Interface Configuration - 34972A Resetting the LAN You can reset the instrument's LAN settings to their default values. • Front-Panel Operation: RESET LAN: NO/YES Enabling and Disabling DHCP You can enable or disable Dynamic Host Configuration Protocol (DHCP). When DHCP is enabled (factory setting), the instrument will try to obtain an IP address from a DHCP server.
34970A Refresh UG.book Page 190 Wednesday, February 17, 2010 12:34 PM Chapter 4 Features and Functions Remote Interface Configuration - 34972A Setting the IP Address You can set the IP address for your 34972A. This menu option assigns the static IP address for the instrument. You must disable DHCP in order to set this on the front panel. The static IP address is applied when DHCP is disabled. If DHCP is enabled, DHCP will auto-assign the IP address.
34970A Refresh UG.book Page 191 Wednesday, February 17, 2010 12:34 PM Chapter 4 Features and Functions Remote Interface Configuration - 34972A Setting the Default Gateway You can set the default gateway for your LAN connection. Contact your network administrator to determine whether subnetting is being used and for the correct address. If DHCP is enabled, DHCP will auto-assign the gateway. This auto-assigned gateway takes precedence over the static gateway assigned with this menu option.
34970A Refresh UG.book Page 192 Wednesday, February 17, 2010 12:34 PM Chapter 4 Features and Functions Calibration Overview Calibration Overview This section gives a brief introduction to the calibration features of the instrument and plug-in modules. For a more detailed discussion of the calibration procedures, see chapter 4 in the 34970A/34972A Service Guide. Calibration Security This feature allows you to enter a security code to prevent accidental or unauthorized calibrations of the instrument.
34970A Refresh UG.book Page 193 Wednesday, February 17, 2010 12:34 PM Chapter 4 Features and Functions Calibration Overview To Unsecure for Calibration You can unsecure the instrument either from the front panel or over the remote interface. The instrument is secured when shipped from the factory and the security code is set to “HP034970” or “AT034972”, depending on the product number. • Once you enter a security code, that code must be used for both frontpanel and remote operation.
34970A Refresh UG.book Page 194 Wednesday, February 17, 2010 12:34 PM Chapter 4 Features and Functions Calibration Overview To Secure Against Calibration You can secure the instrument either from the front panel or over the remote interface. The instrument is secured when shipped from the factory and the security code is set to “HP034970” or “AT034972”, depending on the product number. • Once you enter a security code, that code must be used for both frontpanel and remote operation.
34970A Refresh UG.book Page 195 Wednesday, February 17, 2010 12:34 PM Chapter 4 Features and Functions Calibration Overview Calibration Message The instrument allows you to store one message in calibration memory in the mainframe. For example, you can store such information as the date when the last calibration was performed, the date when the next calibration is due, the instrument’s serial number, or even the name and phone number of the person to contact for a new calibration.
34970A Refresh UG.book Page 196 Wednesday, February 17, 2010 12:34 PM Chapter 4 Features and Functions Calibration Overview Calibration Count You can query the instrument to determine how many calibrations have been performed. Note that your instrument was calibrated before it left the factory. When you receive your instrument, be sure to read the count to determine its initial value.
34970A Refresh UG.book Page 197 Wednesday, February 17, 2010 12:34 PM Chapter 4 Features and Functions Factory Reset State Factory Reset State The table below shows the state of the instrument after a FACTORY RESET from the Sto/Rcl menu or *RST command from the remote interface.
34970A Refresh UG.book Page 198 Wednesday, February 17, 2010 12:34 PM Chapter 4 Features and Functions Instrument Preset State Instrument Preset State The table below shows the state of the instrument after a PRESET from the Sto/Rcl menu or SYSTem:PRESet command from the remote interface.
34970A Refresh UG.book Page 199 Wednesday, February 17, 2010 12:34 PM Chapter 4 Features and Functions Multiplexer Module Default Settings Multiplexer Module Default Settings The table below shows the default settings for each measurement function on the multiplexer modules. When you configure a channel for a particular function, these are the default settings.
34970A Refresh UG.book Page 200 Wednesday, February 17, 2010 12:34 PM Module Overview This section gives a description of each plug-in module, including simplified schematics and block diagrams. A wiring log is also included to make it easy to document your wiring configuration for each module. For complete specifications on each plug-in module, refer to the module sections in chapter 8.
34970A Refresh UG.book Page 201 Wednesday, February 17, 2010 12:34 PM Chapter 4 Features and Functions 34901A 20-Channel Multiplexer 34901A 20-Channel Multiplexer This module is divided into two banks of 10 channels each. Two additional fused channels are available for making direct, calibrated DC or AC current measurements with the internal DMM (external shunts are not required).
34970A Refresh UG.book Page 202 Wednesday, February 17, 2010 12:34 PM Chapter 4 Features and Functions 34901A 20-Channel Multiplexer WIRING LOG Ch Not Used Not Used Name Slot Number: 100 200 300 Function Comments 01 02 03 04 05 06 07 08 09 10 H COM L COM 11* 12* 13* 14* 15* 16* 17* 18* 19* 20* H COM L COM Current Channels Only: 21 22 I COM L COM *4W Sense Channels are paired to Channel (n-10). Refer to the diagrams on page 27 to connect wiring to the module.
34970A Refresh UG.book Page 203 Wednesday, February 17, 2010 12:34 PM Chapter 4 Features and Functions 34902A 16-Channel Multiplexer 34902A 16-Channel Multiplexer This module is divided into two banks of eight channels each. All 16 channels switch both HI and LO inputs, thus providing fully isolated inputs to the internal DMM or an external instrument. When making 4wire resistance measurements, the instrument automatically pairs channel n with channel n+8 to provide the source and sense connections.
34970A Refresh UG.book Page 204 Wednesday, February 17, 2010 12:34 PM Chapter 4 Features and Functions 34902A 16-Channel Multiplexer WIRING LOG Ch Name Slot Number: 100 200 300 Function Comments 01 02 03 04 05 06 07 08 H COM L COM 09* 10* 11* 12* 13* 14* 15* 16* H COM L COM *4W Sense Channels are paired to Channel (n-8). Refer to the diagrams on page 27 to connect wiring to the module.
34970A Refresh UG.book Page 205 Wednesday, February 17, 2010 12:34 PM Chapter 4 Features and Functions 34903A 20-Channel Actuator 34903A 20-Channel Actuator This module contains 20 independent, SPDT (Form C) latching relays. Screw terminals on the module provide access to the Normally-Open, Normally-Closed, and Common contacts for each switch. This module does not connect to the internal DMM.
34970A Refresh UG.book Page 206 Wednesday, February 17, 2010 12:34 PM Chapter 4 Features and Functions 34903A 20-Channel Actuator Slot Number: 100 200 300 WIRING LOG Ch NO NC COM Comments 01 02 03 04 05 06 07 08 09 10 11 12 13 14 15 16 17 18 19 20 NO = Normally Open, NC = Normally Closed Refer to the diagrams on page 27 to connect wiring to the module.
34970A Refresh UG.book Page 207 Wednesday, February 17, 2010 12:34 PM Chapter 4 Features and Functions 34904A 4x8 Matrix Switch 34904A 4x8 Matrix Switch This module contains 32 two-wire crosspoints organized in a 4-row by 8column configuration. You can connect any combination of inputs and outputs at the same time. This module does not connect to the internal DMM. Each crosspoint relay has its own unique channel label representing the row and column.
34970A Refresh UG.book Page 208 Wednesday, February 17, 2010 12:34 PM Chapter 4 Features and Functions 34904A 4x8 Matrix Switch WIRING LOG Row Slot Number: 100 200 300 Name Comments Name Comments 1 2 3 4 Column 1 2 3 4 5 6 7 8 Example: Channel 32 represents Row 3 and Column 2. Refer to the diagrams on page 27 to connect wiring to the module.
34970A Refresh UG.book Page 209 Wednesday, February 17, 2010 12:34 PM Chapter 4 Features and Functions 34905A/6A Dual 4-Channel RF Multiplexers 34905A/6A Dual 4-Channel RF Multiplexers These modules consist of two independent 4-to-1 multiplexers.The channels in each bank are organized in a “tree” structure to provide high isolation and low VSWR. Both banks have a common earth ground. This module does not connect to the internal DMM.
34970A Refresh UG.book Page 210 Wednesday, February 17, 2010 12:34 PM Chapter 4 Features and Functions 34905A/6A Dual 4-Channel RF Multiplexers WIRING LOG Ch Slot Number: 100 200 300 Name Comments 11 12 13 14 COM1 21 22 23 24 COM2 Refer to the diagrams on page 27 to connect wiring to the module. Maximum Input Voltage: 42 V Maximum Input Current: 700 mA Maximum Switching Power: 20 W Ten color-coded cables are included with the module.
34970A Refresh UG.book Page 211 Wednesday, February 17, 2010 12:34 PM Chapter 4 Features and Functions 34907A Multifunction Module 34907A Multifunction Module This module combines two 8-bit ports of digital input/output, a 100 kHz totalizer, and two ±12V analog outputs. For greater flexibility, you can read digital inputs and the totalizer count during a scan.
34970A Refresh UG.
34970A Refresh UG.book Page 213 Wednesday, February 17, 2010 12:34 PM Chapter 4 Features and Functions 34908A 40-Channel Single-Ended Multiplexer 34908A 40-Channel Single-Ended Multiplexer The module is divided into two banks of 20 channels each. All of the 40 channels switch HI only, with a common LO for the module. The module has a built-in thermocouple reference junction to minimize errors due to thermal gradients when measuring thermocouples.
34970A Refresh UG.
34970A Refresh UG.
34970A Refresh UG.
34970A Refresh UG.
34970A Refresh UG.book Page 218 Wednesday, February 17, 2010 12:34 PM Error Messages • Errors are retrieved in first-in-first-out (FIFO) order. The first error returned is the first error that was stored. Errors are cleared as you read them. When you have read all errors from the queue, the ERROR annunciator turns off and the errors are cleared. The instrument beeps once each time an error is generated.
34970A Refresh UG.book Page 219 Wednesday, February 17, 2010 12:34 PM Chapter 5 Error Messages Execution Errors Execution Errors -101 Invalid character An invalid character was found in the command string. You may have used an invalid character such as #, {, $, or % in the command header or within a parameter. Example: CONF:VOLT:DC {@101) -102 Syntax error 4 Invalid syntax was found in the command string.
34970A Refresh UG.book Page 220 Wednesday, February 17, 2010 12:34 PM Chapter 5 Error Messages Execution Errors -114 Header suffix out of range A header suffix is the number that can be appended to the end of some command headers. This error is generated if an invalid number is used. Example: OUTP:ALARM5:SOURCE (“5” is not a valid alarm number) -121 Invalid character in number An invalid character was found in the number specified for a parameter. Example: TRIG:TIMER 12..
34970A Refresh UG.book Page 221 Wednesday, February 17, 2010 12:34 PM Chapter 5 Error Messages Execution Errors -148 Character data not allowed A discrete parameter was received but a character string or a numeric parameter was expected. Check the list of parameters to verify that you have used a valid parameter type. Examples: ROUTE:CLOSE CH101 or DISP:TEXT TESTING (the string must be enclosed in quotes) -151 Invalid string data An invalid character string was received.
34970A Refresh UG.book Page 222 Wednesday, February 17, 2010 12:34 PM Chapter 5 Error Messages Execution Errors -214 Trigger deadlock A trigger deadlock occurs when the trigger source is “BUS” and a READ? command is received. -221 Settings conflict An invalid configuration was requested. This error is most commonly generated when setting alarm limits. Note that the lower limit must always be less than or equal to the upper limit, even if you are using only one of the limits.
34970A Refresh UG.book Page 223 Wednesday, February 17, 2010 12:34 PM Chapter 5 Error Messages Execution Errors -350 Error queue overflow The error queue is full because more than 10 errors (34970A) or 20 errors (34972A) have occurred. No additional errors are stored until you remove errors from the queue. The error queue is cleared by the *CLS (clear status) command or when power is cycled. The errors are also cleared when you read the queue.
34970A Refresh UG.book Page 224 Wednesday, February 17, 2010 12:34 PM Chapter 5 Error Messages Instrument Errors Instrument Errors 111 Channel list: slot number out of range The specified slot number is invalid. The channel number has the form (@scc), where s is the slot number (100, 200, or 300) and cc is the channel number. Example: CONF:VOLT:DC (@404) 112 Channel list: channel number out of range The specified channel number is invalid for the module in the selected slot.
34970A Refresh UG.book Page 225 Wednesday, February 17, 2010 12:34 PM Chapter 5 Error Messages Instrument Errors 203 Memory lost: stored readings This error is reported at power-on to indicate that readings stored in memory from a previous scan have been lost. This error is most likely caused by a dead battery (memory is battery-backed). Refer to the 34970A/34972A Service Guide to replace the internal battery.
34970A Refresh UG.book Page 226 Wednesday, February 17, 2010 12:34 PM Chapter 5 Error Messages Instrument Errors 225 Settings conflict: DMM disabled or missing This command is valid only when the internal DMM is installed and enabled. Use the INSTrument:DMM? command to determine the state of the internal DMM. For more information, see “Internal DMM Disable” on page 167.
34970A Refresh UG.book Page 227 Wednesday, February 17, 2010 12:34 PM Chapter 5 Error Messages Instrument Errors 281 Not able to perform on more than one channel You can perform this operation on only one channel at a time. Check the channel list that you sent with this command to see if it contains more than one channel. This error is generated by the ROUTe:MON and DATA:LAST? commands.
34970A Refresh UG.book Page 228 Wednesday, February 17, 2010 12:34 PM Chapter 5 Error Messages Instrument Errors 306 Part of a 4-wire pair For 4-wire resistance measurements, the instrument automatically pairs channel n with channel n+10 (34901A) or n+8 (34902A) to provide the source and sense connections. To change the configuration on the upper channel in a 4-wire pair, you must first reconfigure the lower channel to a measurement function other than 4-wire resistance.
34970A Refresh UG.book Page 229 Wednesday, February 17, 2010 12:34 PM Chapter 5 Error Messages Instrument Errors 401 Mass storage error: failed to create file The file was not created on the USB drive. 402 Mass storage error: failed to open file The file was not opened on the USB drive. 403 Mass storage error: failed to close file The file was not closed on the USB drive. 404 Mass storage error: file write error The file data was not written on the USB drive.
34970A Refresh UG.book Page 230 Wednesday, February 17, 2010 12:34 PM Chapter 5 Error Messages Instrument Errors 414 Directory already exists The instrument was unable to create new directory because a directory with that name already exists on the USB drive. 415 File not found The file does not exist on the USB drive. 416 Path not found The directory does not exist on the USB drive. 417 File not opened for writing The instrument failed to open the file for writing on the USB drive.
34970A Refresh UG.book Page 231 Wednesday, February 17, 2010 12:34 PM Chapter 5 Error Messages Instrument Errors 450 Overrun during data collection: readings lost in USB transfer Internal error: readings were collected too fast and were not buffered for output to the USB drive. 451 Overrun during USB output: readings lost in USB transfer Internal error: USB write operation was unable to keep up with data collection.
34970A Refresh UG.book Page 232 Wednesday, February 17, 2010 12:34 PM Chapter 5 Error Messages Instrument Errors 459 Logging to USB was stopped Data logging was stopped prior to completion due to an abort or some other error condition. 460 Logging to USB was stopped after 2^32 sweeps of data Instrument is only able to capture 2^32 (~4.3 billion) sweeps worth of data on an external USB drive 461 Memory lost: non-volatile settings; USB drive Data in non-volatile memory was lost or corrupted.
34970A Refresh UG.book Page 233 Wednesday, February 17, 2010 12:34 PM Chapter 5 Error Messages Instrument Errors 470 Measurement was reconfigured; Cannot save configuration data Measurement configuration no longer agrees with the corresponding set of readings. Configuration data will not be saved to the USB drive. 471 USB operation aborted; Cannot save configuration data An abort or device clear was received while fetching configuration data from secondary processor.
34970A Refresh UG.
34970A Refresh UG.book Page 235 Wednesday, February 17, 2010 12:34 PM Chapter 5 Error Messages Self-Test Errors Self-Test Errors The following errors indicate failures that may occur during a self-test. Refer to the 34970A/34972A Service Guide for more information.
34970A Refresh UG.book Page 236 Wednesday, February 17, 2010 12:34 PM Chapter 5 Error Messages Calibration Errors Calibration Errors The following errors indicate failures that may occur during a calibration. Refer to the 34970A/34972A Service Guide for more information. 701 Cal: security disabled by jumper The calibration security feature has been disabled with a jumper inside the instrument. When applicable, this error will occur at power-on to alert you that the instrument is unsecured.
34970A Refresh UG.book Page 237 Wednesday, February 17, 2010 12:34 PM Chapter 5 Error Messages Calibration Errors NOTE: The following error messages indicate possible hardware failures within the instrument. If any of the following errors occur, contact your nearest Agilent Service Center for repair.
34970A Refresh UG.
34970A Refresh UG.book Page 239 Wednesday, February 17, 2010 12:34 PM Chapter 5 Error Messages Plug-In Module Errors Plug-In Module Errors NOTE: The following error messages indicate possible hardware failures within the instrument. If any of the following errors occur, contact your nearest Agilent Service Center for repair.
34970A Refresh UG.
34970A Refresh UG.
34970A Refresh UG.book Page 242 Wednesday, February 17, 2010 12:34 PM Application Programs This chapter contains several example programs to help you develop programs for your specific measurement application. See the Agilent 34970A/34972A Programmer’s Reference Help for details on the SCPI language for the instrument. The examples in this chapter have been tested on a PC running on Windows 95.
34970A Refresh UG.book Page 243 Wednesday, February 17, 2010 12:34 PM Chapter 6 Application Programs Example Programs for Excel 7.0 Example Programs for Excel 7.0 This section contains two example programs written using Excel macros (Visual Basic® for Applications) to control the 34970A/34972A. Using Excel, you can send SCPI commands to configure the instrument and then record measurement data on the Excel spreadsheet. To write an Excel macro you must first open a module in Excel.
34970A Refresh UG.book Page 244 Wednesday, February 17, 2010 12:34 PM Chapter 6 Application Programs Example Programs for Excel 7.0 Excel 7.0 Example: takeReadings Macro ’""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""" ’This Excel Macro (Visual Basic) configures the 34970A for scanning with the 34901A, ’34902A, or 34908A multiplexer modules. When this subroutine is executed, it will ’take the specified number of readings on the selected channel.
34970A Refresh UG.book Page 245 Wednesday, February 17, 2010 12:34 PM Chapter 6 Application Programs Example Programs for Excel 7.0 Excel 7.0 Example: Port Configuration Macro Option Explicit ’ Declarations for VISA.DLL ’ Basic I/O Operations Private Declare Function viOpenDefaultRM Lib "VISA32.DLL" Alias "#141" (sesn As Long) As Long Private Declare Function viOpen Lib "VISA32.
34970A Refresh UG.book Page 246 Wednesday, February 17, 2010 12:34 PM Chapter 6 Application Programs Example Programs for Excel 7.0 Sub OpenPort() ’"""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""" ’ Be sure that the GPIB address has been set in the ’VISAaddr’ variable ’ before calling this routine.
34970A Refresh UG.book Page 247 Wednesday, February 17, 2010 12:34 PM Chapter 6 Application Programs Example Programs for Excel 7.0 Excel 7.0 Example: ScanChannels Macro ’""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""" ’ This Excel Macro (Visual Basic) configures the 34970A for scanning with the 34901A, ’ 34902A, or 34908A multiplexer modules. When this subroutine is executed, it will ’ scan 5 channels and display the readings on a spreadsheet.
34970A Refresh UG.book Page 248 Wednesday, February 17, 2010 12:34 PM Chapter 6 Application Programs Example Programs for Excel 7.0 ’ Set up the scan trigger parameters after configuring the channels in the scan list ’ using the CONFigure command. The following commands configure the scan interval.
34970A Refresh UG.book Page 249 Wednesday, February 17, 2010 12:34 PM Chapter 6 Application Programs Example Programs for Excel 7.0 Sub makeDataTable(Channel As Integer, columnIndex As Integer) ’ This routine will take the parsed data in row ’1’ for a channel and put it into a ’ table. ’Channel’ determines the row of the table and ’columnIndex’ determines the ’ column (scan sweep count). ’ The number of comma-delimited fields returned per channel is determined by the ’ FORMat:READing commands.
34970A Refresh UG.book Page 250 Wednesday, February 17, 2010 12:34 PM Chapter 6 Application Programs Example Programs for C and C++ Example Programs for C and C++ The following C programming examples show you how to send and receive formatted I/O. For more information on non-formatted I/O, refer to the Agilent VISA User’s Guide. The examples in this section show you how to use the SCPI commands for the instrument with the VISA functionality and does not include error trapping.
34970A Refresh UG.book Page 251 Wednesday, February 17, 2010 12:34 PM Chapter 6 Application Programs Example Programs for C and C++ C/C++ Example: dac_out.c /* dac_out.c /************************************************************************************* * Required: 34907A Multifunction Module in slot 200; VISA library * * This program uses the VISA library to communicate with the 34970A. * * The program queries slot 200 and displays the response.
34970A Refresh UG.book Page 252 Wednesday, February 17, 2010 12:34 PM Chapter 6 Application Programs Example Programs for C and C++ C/C++ Example: stat_reg.c /* stat_reg.c /************************************************************************************ * Required: VISA library. * * This program demonstrates the use of the 34970A Status Registers * * for an alarm and Operation Complete (OPC) and for enabling and receiving * * an SRQ interrupt.
34970A Refresh UG.book Page 253 Wednesday, February 17, 2010 12:34 PM Chapter 6 Application Programs Example Programs for C and C++ do{ /* Stay in loop until the srqFlag goes negative */ index = 1; for (count = 0; count <45; count++) { index = 0; printf(".
34970A Refresh UG.
34970A Refresh UG.
34970A Refresh UG.book Page 256 Wednesday, February 17, 2010 12:34 PM Tutorial This chapter describes methods that you can use to reduce errors that can affect your measurements. You will also find information to help you better understand how the 34970A/34972A makes measurements and what you can do to get the best results.
34970A Refresh UG.book Page 257 Wednesday, February 17, 2010 12:34 PM Chapter 7 Tutorial System Cabling and Connections System Cabling and Connections This section describes methods to reduce measurement errors that can be introduced by your system cabling. Many system cabling errors can be reduced or eliminated by selecting the proper cable and grounding scheme for your system. Cable Specifications 4 A wide variety of general-purpose and custom cables are available.
34970A Refresh UG.book Page 258 Wednesday, February 17, 2010 12:34 PM Chapter 7 Tutorial System Cabling and Connections • Cable Resistance – Varies with wire gauge size and cable length. Use the largest gauge wire possible and try to keep the cable lengths as short as possible to minimize the cable resistance. The following table lists typical cable resistance for copper wire of several gauge sizes (the temperature coefficient for copper wire is 0.35% per °C).
34970A Refresh UG.book Page 259 Wednesday, February 17, 2010 12:34 PM Chapter 7 Tutorial System Cabling and Connections Grounding Techniques One purpose of grounding is to avoid ground loops and minimize noise. Most systems should have at least three separate ground returns. 1. One ground for signals. You may also want to provide separate signal grounds between high-level signals, low-level signals, and digital signals. 2.
34970A Refresh UG.book Page 260 Wednesday, February 17, 2010 12:34 PM Chapter 7 Tutorial System Cabling and Connections Shielding Techniques Shielding against noise must address both capacitive (electrical) and inductive (magnetic) coupling. The addition of a grounded shield around the conductor is highly effective against capacitive coupling. In switching networks, this shielding often takes the form of coaxial cables and connectors.
34970A Refresh UG.book Page 261 Wednesday, February 17, 2010 12:34 PM Chapter 7 Tutorial System Cabling and Connections Sources of System Cabling Errors Radio Frequency Interference Most voltage-measuring instruments can generate false readings in the presence of large, high-frequency signals. Possible sources of high-frequency signals include nearby radio and television transmitters, computer monitors, and cellular telephones.
34970A Refresh UG.book Page 262 Wednesday, February 17, 2010 12:34 PM Chapter 7 Tutorial System Cabling and Connections Thermal EMF Errors Thermoelectric voltages are the most common source of error in low-level DC voltage measurements. Thermoelectric voltages are generated when you make circuit connections using dissimilar metals at different temperatures. Each metal-to-metal junction forms a thermocouple, which generates a voltage proportional to the junction temperature difference.
34970A Refresh UG.book Page 263 Wednesday, February 17, 2010 12:34 PM Chapter 7 Tutorial System Cabling and Connections Noise Caused by Ground Loops When measuring voltages in circuits where the internal DMM and the device-under-test are both referenced to a common earth ground, a ground loop is formed. As shown below, any voltage difference between the two ground reference points (Vground) causes a current to flow through the LO measurement lead.
34970A Refresh UG.book Page 264 Wednesday, February 17, 2010 12:34 PM Chapter 7 Tutorial System Cabling and Connections Low-Level AC Measurement Errors When measuring AC voltages less than 100 mV, be aware that these measurements are especially susceptible to errors introduced by extraneous noise sources. An exposed test lead will act as an antenna and the internal DMM will measure the signals received. The entire measurement path, including the power line, act as a loop antenna.
34970A Refresh UG.book Page 265 Wednesday, February 17, 2010 12:34 PM Chapter 7 Tutorial Measurement Fundamentals Measurement Fundamentals This section explains how the 34970A/34972A makes measurements and discusses the most common sources of error related to these measurements. The Internal DMM 4 The internal DMM provides a universal input front-end for measuring a variety of transducer types without the need for additional external signal conditioning.
34970A Refresh UG.book Page 266 Wednesday, February 17, 2010 12:34 PM Chapter 7 Tutorial Measurement Fundamentals Rejecting Power-Line Noise Voltages A desirable characteristic of an integrating analog-to-digital (A/D) converter is its ability to reject spurious signals. Integrating techniques reject power-line related noise present with DC signals on the input. This is called normal mode rejection or NMR.
34970A Refresh UG.book Page 267 Wednesday, February 17, 2010 12:34 PM Chapter 7 Tutorial Measurement Fundamentals Temperature Measurements A temperature transducer measurement is typically either a resistance or voltage measurement converted to an equivalent temperature by software conversion routines inside the instrument. The mathematical conversion is based on specific properties of the various transducers.
34970A Refresh UG.book Page 268 Wednesday, February 17, 2010 12:34 PM Chapter 7 Tutorial Measurement Fundamentals RTD Measurements An RTD is constructed of a metal (typically platinum) that changes resistance with a change in temperature in a precisely known way. The internal DMM measures the resistance of the RTD and then calculates the equivalent temperature. An RTD has the highest stability of the temperature transducers. The output from an RTD is also very linear.
34970A Refresh UG.book Page 269 Wednesday, February 17, 2010 12:34 PM Chapter 7 Tutorial Measurement Fundamentals Thermocouple Measurements A thermocouple converts temperature to voltage. When two wires composed of dissimilar metals are joined, a voltage is generated. The voltage is a function of the junction temperature and the types of metals in the thermocouple wire.
34970A Refresh UG.book Page 270 Wednesday, February 17, 2010 12:34 PM Chapter 7 Tutorial Measurement Fundamentals An ice bath is used to create a known reference temperature (0 °C). Once the reference temperature and thermocouple type are known, the temperature of the measurement thermocouple can be calculated. Internal DMM Ice Bath The T-type thermocouple is a unique case since one of the conductors (copper) is the same metal as the internal DMM’s input terminals.
34970A Refresh UG.book Page 271 Wednesday, February 17, 2010 12:34 PM Chapter 7 Tutorial Measurement Fundamentals To make a more accurate measurement, you should extend the copper test leads of the internal DMM closer to the measurement and hold the connections to the thermocouple at the same temperature. Internal DMM Measurement Thermocouple 4 Ice Bath Reference Thermocouple This circuit will give accurate temperature measurements.
34970A Refresh UG.book Page 272 Wednesday, February 17, 2010 12:34 PM Chapter 7 Tutorial Measurement Fundamentals In some measurement situations, however, it would be nice to remove the need for an ice bath (or any other fixed external reference). To do this, an isothermal block is used to make the connections. An isothermal block is an electrical insulator, but a good heat conductor. The additional thermocouples created at J1 and J2 are now held at the same temperature by the isothermal block.
34970A Refresh UG.book Page 273 Wednesday, February 17, 2010 12:34 PM Chapter 7 Tutorial Measurement Fundamentals Thermocouple Types T/C Type Pos (+) Lead Neg (-) Lead Temperature Range B Platinum -30% Rhodium Platinum -60% Rhodium 250°C - 1820°C U.S. Gray Red British N/A N/A DIN Red Gray Japanese Red Gray French N/A N/A Probe Accuracy ±0.5°C Comments High Temperature. Beware of contamination. Do not insert in metal tubes. 4 J Iron U.S.
34970A Refresh UG.book Page 274 Wednesday, February 17, 2010 12:34 PM Chapter 7 Tutorial Measurement Fundamentals Sources of Error in Thermocouple Measurements Reference Junction Error A thermocouple is typically formed by welding or soldering two wires together to make the junction. Soldering introduces a third metal into the junction. Provided that both sides of the thermocouple are at the same temperature, the third metal has little effect.
34970A Refresh UG.book Page 275 Wednesday, February 17, 2010 12:34 PM Chapter 7 Tutorial Measurement Fundamentals Shunt Impedance The insulation used for thermocouple wire and extension wire can be degraded by high temperatures or corrosive atmospheres. These breakdowns appear as a resistance in parallel with the thermocouple junction. This is especially apparent in systems using a small gauge wire where the series resistance of the wire is high.
34970A Refresh UG.book Page 276 Wednesday, February 17, 2010 12:34 PM Chapter 7 Tutorial Measurement Fundamentals DC Voltage Measurements To make a useful DC meter, a “front-end” is required to condition the input before the analog-to-digital conversion. Signal conditioning increases the input resistance, amplifies small signals, and attenuates large signals to produce a selection of measuring ranges.
34970A Refresh UG.book Page 277 Wednesday, February 17, 2010 12:34 PM Chapter 7 Tutorial Measurement Fundamentals Sources of Error in DC Voltage Measurements Common Mode Rejection Ideally, the internal DMM is completely isolated from earth-referenced circuits. However, there is finite resistance and capacitance between the input LO terminal and earth ground.
34970A Refresh UG.book Page 278 Wednesday, February 17, 2010 12:34 PM Chapter 7 Tutorial Measurement Fundamentals Noise Caused by Injected Current Residual capacitances in the instrument’s power transformer cause small currents to flow from the LO terminal of the internal DMM to earth ground. The frequency of the “injected current” is the power line frequency or possibly harmonics of the power line frequency. The injected current is dependent upon the power line configuration and frequency.
34970A Refresh UG.book Page 279 Wednesday, February 17, 2010 12:34 PM Chapter 7 Tutorial Measurement Fundamentals Loading Errors Due to Input Resistance Measurement loading errors occur when the resistance of the device-under-test (DUT) is an appreciable percentage of the instrument’s own input resistance. The diagram below shows this error source.
34970A Refresh UG.book Page 280 Wednesday, February 17, 2010 12:34 PM Chapter 7 Tutorial Measurement Fundamentals Loading Errors Due to Input Bias Current The semiconductor devices used in the input circuits of the internal DMM have slight leakage currents called bias currents. The effect of the input bias current is a loading error at the internal DMM’s input terminals.
34970A Refresh UG.book Page 281 Wednesday, February 17, 2010 12:34 PM Chapter 7 Tutorial Measurement Fundamentals AC Voltage Measurements The main purpose of an AC “front end” is to change an AC voltage input into a DC voltage which can be measured by the ADC. Signal Conditioning for AC Measurements Input signal conditioning for AC voltage measurements includes both attenuation and amplification.
34970A Refresh UG.book Page 282 Wednesday, February 17, 2010 12:34 PM Chapter 7 Tutorial Measurement Fundamentals True RMS AC Measurements True RMS responding multimeters measure the “heating” potential of an applied voltage. Unlike an “average responding” measurement, a true RMS measurement is used to determine the power dissipated in a resistor. The power is proportional to the square of the measured true RMS voltage, independent of waveshape.
34970A Refresh UG.book Page 283 Wednesday, February 17, 2010 12:34 PM Chapter 7 Tutorial Measurement Fundamentals Making High-Speed AC Measurements The internal DMM’s AC voltage and AC current functions implement three low-frequency filters. These filters allow you to trade-off low frequency accuracy for faster scanning speed. The fast filter settles in 0.12 seconds and is useful for measurements above 200 Hz. The medium filter settles in 1 second and is useful for measurements above 20 Hz.
34970A Refresh UG.book Page 284 Wednesday, February 17, 2010 12:34 PM Chapter 7 Tutorial Measurement Fundamentals Sources of Error in AC Voltage Measurements Many of the errors associated with DC voltage measurements also apply to AC voltage measurements. Additional errors unique to AC voltage measurements are described in this section.
34970A Refresh UG.book Page 285 Wednesday, February 17, 2010 12:34 PM Chapter 7 Tutorial Measurement Fundamentals Example: Calculating Measurement Error Calculate the approximate measurement error for a pulse train input with a crest factor of 3 and a fundamental frequency of 20 kHz. The internal DMM is set to the 1 V range. For this example, use the 90-day accuracy specifications of ± (0.05% of reading + 0.04% of range), as shown in chapter 8. Errorsine = ±(0.05% + 0.04%) = ±0.
34970A Refresh UG.book Page 286 Wednesday, February 17, 2010 12:34 PM Chapter 7 Tutorial Measurement Fundamentals AC Loading Errors In the AC voltage function, the input of the internal DMM appears as a 1 M resistance in parallel with 150 pF of capacitance. The cabling that you use to connect signals to the instrument will also add additional capacitance and loading. The table below shows the approximate input resistance at various frequencies.
34970A Refresh UG.book Page 287 Wednesday, February 17, 2010 12:34 PM Chapter 7 Tutorial Measurement Fundamentals Low-Level AC Measurement Errors When measuring AC voltages less than 100 mV, be aware that these measurements are especially susceptible to errors introduced by extraneous noise sources. An exposed test lead will act as an antenna and the internal DMM will measure the signals received. The entire measurement path, including the power line, act as a loop antenna.
34970A Refresh UG.book Page 288 Wednesday, February 17, 2010 12:34 PM Chapter 7 Tutorial Measurement Fundamentals Measurements Below Full Scale You can make the most accurate AC measurements when the internal DMM is at full scale of the selected range. Autoranging occurs at 10% and 120% of full scale. This enables you to measure some inputs at full scale on one range and 10% of full scale on the next higher range. Note that the measurement accuracy will be significantly different for the two cases.
34970A Refresh UG.book Page 289 Wednesday, February 17, 2010 12:34 PM Chapter 7 Tutorial Measurement Fundamentals Current Measurements Current measurements are allowed only on the 34901A module. An ammeter senses the current flowing through its input connections – approximating a short circuit between its input terminals. An ammeter must be connected in series with the circuit or device being measured such that current flows through both the meter and the test circuit.
34970A Refresh UG.book Page 290 Wednesday, February 17, 2010 12:34 PM Chapter 7 Tutorial Measurement Fundamentals Sources of Error in DC Current Measurements When you connect the internal DMM in series with a test circuit to measure current, a measurement error is introduced. The error is caused by the DMM’s series burden voltage. A voltage is developed across the wiring resistance and current shunt resistance of the internal DMM as shown below.
34970A Refresh UG.book Page 291 Wednesday, February 17, 2010 12:34 PM Chapter 7 Tutorial Measurement Fundamentals Resistance Measurements An ohmmeter measures the DC resistance of a device or circuit connected to its input. Resistance measurements are performed by supplying a known DC current to an unknown resistance and measuring the DC voltage drop.
34970A Refresh UG.book Page 292 Wednesday, February 17, 2010 12:34 PM Chapter 7 Tutorial Measurement Fundamentals The 4-wire ohms method is used in systems where lead resistances can become quite large and variable and in automated test applications where cable lengths can be quite long. The 4-wire ohms method has the obvious disadvantage of requiring twice as many switches and twice as many wires as the 2-wire method.
34970A Refresh UG.book Page 293 Wednesday, February 17, 2010 12:34 PM Chapter 7 Tutorial Measurement Fundamentals Offset Compensation Most connections in a system use materials that produce small DC voltages due to dissimilar metal-to-metal contact (thermocouple effect) or electrochemical batteries (for a description of the thermocouple effect, see page 262). These DC voltages also add errors to resistance measurements.
34970A Refresh UG.book Page 294 Wednesday, February 17, 2010 12:34 PM Chapter 7 Tutorial Measurement Fundamentals Sources of Error in Resistance Measurements External Voltages Any voltages present in the system cabling or connections will affect a resistance measurement. The effects of some of these voltages can be overcome by using offset compensation (as described on the previous page). Settling Time Effects The internal DMM has the ability to insert automatic measurement settling delays.
34970A Refresh UG.book Page 295 Wednesday, February 17, 2010 12:34 PM Chapter 7 Tutorial Measurement Fundamentals Strain Gage Measurements Although the instrument does not directly support strain measurements, you can measure a strain gage using a 4-wire resistance measurement with scaling. However, BenchLink Data Logger 3 software has built-in strain gage measurement capability. When a force is applied to a body, the body deforms. The deformation per unit length is called strain ().
34970A Refresh UG.book Page 296 Wednesday, February 17, 2010 12:34 PM Chapter 7 Tutorial Measurement Fundamentals Strain Sensors The metal foil resistance strain gage is by far the most widely used strain measurement sensor. It consists of a thin metallic foil grid bonded to a thin insulating, adhesive backing. The resistance of the foil varies linearly with strain. Strain in the test body is simply the ratio of the foil’s strained to unstrained resistance: = R / R.
34970A Refresh UG.book Page 297 Wednesday, February 17, 2010 12:34 PM Chapter 7 Tutorial Measurement Fundamentals Making Strain Gage Measurements A Wheatstone bridge is commonly used to enable instruments with low-sensitivity measuring capabilities to measure small resistance changes common in strain measurements. Instruments with high-resolution resistance measuring capabilities, like the 34970A/34972A internal DMM, can directly measure small resistance changes with high precision and linearity.
34970A Refresh UG.book Page 298 Wednesday, February 17, 2010 12:34 PM Chapter 7 Tutorial Measurement Fundamentals Frequency and Period Measurements The internal DMM uses a reciprocal counting technique to measure frequency and period. This method generates constant measurement resolution for any input frequency. The internal DMM’s AC voltage measurement section performs input signal conditioning for frequency and period measurements. Reset Analog Input Signal Conditioning Counter F/F Latch .01s .
34970A Refresh UG.book Page 299 Wednesday, February 17, 2010 12:34 PM Chapter 7 Tutorial Measurement Fundamentals Sources of Error in Frequency and Period Measurements The internal DMM’s AC voltage measurement section performs input signal conditioning. All frequency counters are susceptible to errors when measuring low-voltage, low-frequency signals. The effects of both internal noise and external noise pickup are critical when measuring “slow” signals. The error is inversely proportional to frequency.
34970A Refresh UG.book Page 300 Wednesday, February 17, 2010 12:34 PM Chapter 7 Tutorial Low-Level Signal Multiplexing and Switching Low-Level Signal Multiplexing and Switching Low-level multiplexers are available in the following types: one-wire, 2-wire, and 4-wire. The following sections in this chapter describe each type of multiplexer. The following low-level multiplexer modules are available with the 34970A.
34970A Refresh UG.book Page 301 Wednesday, February 17, 2010 12:34 PM Chapter 7 Tutorial Low-Level Signal Multiplexing and Switching One-Wire (Single-Ended) Multiplexers On the 34908A multiplexer, all of the 40 channels switch the HI input only, with a common LO for the module. The module also provides a thermocouple reference junction for making thermocouple measurements (for more information on the purpose of an isothermal block, see page 272).
34970A Refresh UG.book Page 302 Wednesday, February 17, 2010 12:34 PM Chapter 7 Tutorial Low-Level Signal Multiplexing and Switching Four-Wire Multiplexers You can make 4-wire ohms measurements using the 34901A and 34902A multiplexers. For a 4-wire ohms measurement, the channels are divided into two independent banks by opening the bank relay. For 4-wire measurements, the instrument automatically pairs channel n with channel n+10 (34901A) or n+8 (34902A) to provide the source and sense connections.
34970A Refresh UG.book Page 303 Wednesday, February 17, 2010 12:34 PM Chapter 7 Tutorial Low-Level Signal Multiplexing and Switching Signal Routing and Multiplexing When used stand-alone for signal routing (not scanning or connected to the internal DMM), multiple channels on the 34901A and 34902A multiplexers can be closed at the same time. You must be careful that this does not create a hazardous condition (for example, connecting two power sources together). Note that a multiplexer is not directional.
34970A Refresh UG.book Page 304 Wednesday, February 17, 2010 12:34 PM Chapter 7 Tutorial Low-Level Signal Multiplexing and Switching Sources of Error in Multiplexing and Switching Noise can be coupled inside a switch by the drive circuitry, by switch thermal EMFs, or by coupling among signal paths. Noise can also be generated outside the network and conducted or coupled into the switch. Although noise problems apply to the entire system, they can become especially acute for switching.
34970A Refresh UG.book Page 305 Wednesday, February 17, 2010 12:34 PM Chapter 7 Tutorial Low-Level Signal Multiplexing and Switching The 34901A and 34902A multiplexers have an additional relay, called a bank switch or tree switch, which helps reduce channel-to- channel noise (Cadj). The multiplexer channels are divided into two banks. The bank switch isolates one bank of channels from the other, effectively removing any parallel adjacent capacitance from the isolated bank.
34970A Refresh UG.book Page 306 Wednesday, February 17, 2010 12:34 PM Chapter 7 Tutorial Actuators and General-Purpose Switching Actuators and General-Purpose Switching The 34903A Actuator provides 20 independent, isolated SPDT (single-pole, double-throw) or Form C switches. This module offers simple on-off switching which you can use to control power devices or for custom switching applications. For example, you can use an actuator to build a simple resistance ladder as shown below.
34970A Refresh UG.book Page 307 Wednesday, February 17, 2010 12:34 PM Chapter 7 Tutorial Actuators and General-Purpose Switching Snubber Circuits Whenever a relay contact opens or closes, electrical breakdown or arching can occur between the contacts. This can cause high-frequency noise radiation, voltage and current surges, and physical damage to the relay contacts. A breadboard area is provided on the 34903A to implement custom circuitry such as simple filters, snubbers, and voltage dividers.
34970A Refresh UG.book Page 308 Wednesday, February 17, 2010 12:34 PM Chapter 7 Tutorial Actuators and General-Purpose Switching The maximum value for Rp is usually made equal to the load resistance RL. Therefore, the limits on Rp can be stated as: V--------- Rp RL I max Note that the actual value of the current (Io) in a circuit is determined by the equation: VI o = -----RL Where V is the peak value of the source voltage and RL is the resistance of the load.
34970A Refresh UG.book Page 309 Wednesday, February 17, 2010 12:34 PM Chapter 7 Tutorial Actuators and General-Purpose Switching Using Attenuators Provisions have been made on the 34903A circuit board for installing simple attenuators or filter networks. An attenuator is composed of two resistors that act as a voltage divider. A typical attenuator circuit is shown below.
34970A Refresh UG.book Page 310 Wednesday, February 17, 2010 12:34 PM Chapter 7 Tutorial Matrix Switching Matrix Switching A matrix switch connects multiple inputs to multiple outputs and therefore offers more switching flexibility than a multiplexer. Use a matrix for switching low-frequency (less than 10 MHz) signals only. A matrix is arranged in rows and columns. For example, a simple 3x3 matrix could be used to connect three sources to three test points as shown below.
34970A Refresh UG.book Page 311 Wednesday, February 17, 2010 12:34 PM Chapter 7 Tutorial Matrix Switching Combining Matrices You can combine two or more matrix switches to provide more complex switching. For example, the 34904A provides a 4-row by 8-column matrix. You can combine two of these modules as either a 4-row by 16-column matrix or an 8-row by 8-column matrix. An 8x8 matrix is shown below.
34970A Refresh UG.book Page 312 Wednesday, February 17, 2010 12:34 PM Chapter 7 Tutorial RF Signal Multiplexing RF Signal Multiplexing A special type of multiplexer is the RF multiplexer. This type of multiplexer uses special components to maintain a 50 or 75 impedance in the signal line being switched. In a test system, these switches are often used to route a test signal from a signal source to the device-under-test. The switches are bi-directional.
34970A Refresh UG.book Page 313 Wednesday, February 17, 2010 12:34 PM Chapter 7 Tutorial RF Signal Multiplexing Sources of Error in RF Switching Impedance mismatching can cause a variety of errors in an RF multiplexing system. These errors can cause distorted waveforms, overvoltage, or undervoltage conditions. To minimize RF impedance mismatching: • Use the correct cable and connector for the circuit impedance (50 or 75).
34970A Refresh UG.book Page 314 Wednesday, February 17, 2010 12:34 PM Chapter 7 Tutorial Multifunction Module Multifunction Module Digital Input The 34907A module has two non-isolated 8-bit input/output ports which you can use for reading digital patterns. • You can read the live status of the bits on the port or you can configure a scan to include a digital read. • You can generate an alarm when a specific bit pattern or bit pattern change is detected on an input channel.
34970A Refresh UG.book Page 315 Wednesday, February 17, 2010 12:34 PM Chapter 7 Tutorial Multifunction Module Digital Output The 34907A module has two non-isolated 8-bit input/output ports, which you can use for outputting digital patterns. You can combine the two ports to output a 16-bit word. A simplified diagram of a single output bit is shown below. External Circuit +5 V 4 +V 10 k Output I/O Line (1 of 16) 0.2 • Each output bit is capable of directly driving up to 10 TTL loads (less than 1 mA).
34970A Refresh UG.book Page 316 Wednesday, February 17, 2010 12:34 PM Chapter 7 Tutorial Multifunction Module Using an External Pull-Up In general, an external pull-up is required only when you want to set the output “high” value greater than TTL levels. For example, to use a +12V external power supply, the value of the external pull-up resistor is calculated as follows: V cc = 12 VDC Imax = Iout low x safety factor = 1 mA x 0.5 + 0.5 ma V cc 12 = 24 k R = ---------- = ----------------· I max 0.
34970A Refresh UG.book Page 317 Wednesday, February 17, 2010 12:34 PM Chapter 7 Tutorial Multifunction Module Totalizer The 34907A module has a 26-bit totalizer which can count pulses at a 100 kHz rate. You can manually read the totalizer count or you can configure a scan to read the count.
34970A Refresh UG.book Page 318 Wednesday, February 17, 2010 12:34 PM Chapter 7 Tutorial Multifunction Module • You can control when the totalizer actually records counts by providing a gate signal (G and G terminals on the module). A TTL high signal applied to the “G” terminal enables counting and a low signal disables counting. A TTL low signal applied to the “ G ” terminal enables counting and a high signal disables counting. The totalizer only counts when both terminals are enabled.
34970A Refresh UG.book Page 319 Wednesday, February 17, 2010 12:34 PM Chapter 7 Tutorial Multifunction Module Voltage (DAC) Output The 34907A module has two analog outputs capable of outputting calibrated voltages between ±12 volts with 16 bits of resolution. Each DAC (Digital-to-Analog Converter) channel can be used as a programmable voltage source for analog input to other devices.
34970A Refresh UG.book Page 320 Wednesday, February 17, 2010 12:34 PM Chapter 7 Tutorial Multifunction Module DAC Errors The output of a DAC varies with temperature. If possible, you should operate the instrument at a stable temperature and as close as possible to the calibration temperature of the DAC for greater accuracy. The output of a DAC also exhibits two other types of errors: differential error and integral error. • Differential Error refers to the smallest possible change in voltage.
34970A Refresh UG.book Page 321 Wednesday, February 17, 2010 12:34 PM Chapter 7 Tutorial Relay Life and Preventive Maintenance Relay Life and Preventive Maintenance The 34970A/34972A Relay Maintenance System automatically counts the cycles on each relay in the instrument and stores the total count in nonvolatile memory on each switch module. Use this feature to track relay failures and predict system maintenance requirements.
34970A Refresh UG.book Page 322 Wednesday, February 17, 2010 12:34 PM Chapter 7 Tutorial Relay Life and Preventive Maintenance Relay Life As a relay is used, the contacts begin to wear and the resistance of the closed contacts increases. The initial contact resistance of a relay is typically 50 m (plus lead resistance). When the contact resistance exceeds 20 to 50 times its initial value, the contact resistance becomes very erratic and the relay should probably be replaced.
34970A Refresh UG.book Page 323 Wednesday, February 17, 2010 12:34 PM Chapter 7 Tutorial Relay Life and Preventive Maintenance Switching Frequency Relay contacts heat up as they switch significant power. The heat is dissipated through the leads and the body of the relay. As you increase the switching frequency to near its maximum, heat cannot dissipate before the next cycle. The contact temperature rises and the life of the relay is reduced.
34970A Refresh UG.
34970A Refresh UG.
34970A Refresh UG.book Page 326 Wednesday, February 17, 2010 12:34 PM Chapter 8 Specifications DC, Resistance, and Temperature Accuracy Specifications DC, Resistance, and Temperature Accuracy Specifications ± (% of reading + % of range) [1] Includes measurement error, switching error, and transducer conversion error Function Range[3] Test Current or Burden Voltage Temperature Coefficient /°C 0 °C - 18 °C 28 °C - 55 °C 24 Hour[2] 23 °C ± 1 °C 90 Day 23 °C ± 5 °C 0.0030 + 0.0035 0.0020 + 0.0006 0.
34970A Refresh UG.book Page 327 Wednesday, February 17, 2010 12:34 PM Chapter 8 Specifications DC Measurement and Operating Characteristics DC Measurement and Operating Characteristics DC Measurement Characteristics [1] DC Voltage Measurement Method: A/D Linearity: Input Resistance: 100 mV, 1V, 10 V ranges 100 V, 300 V ranges Input Bias Current: Input Protection: Resistance Measurement Method: Continuously Integrating Multi-slope III A/D Converter 0.0002% of reading + 0.
34970A Refresh UG.book Page 328 Wednesday, February 17, 2010 12:34 PM Chapter 8 Specifications AC Accuracy Specifications AC Accuracy Specifications ± (% of reading + % of range) [1] Includes measurement error, switching error, and transducer conversion error Function True RMS AC Voltage [4] Frequency and Period[6] True RMS AC Current 34901A Only Range[3] 24 Hour[2] 23 °C ± 1 °C Frequency 1 Year 23 °C ± 5 °C Temperature Coefficient /°C 0 °C - 18 °C 28 °C - 55 °C 100.
34970A Refresh UG.
34970A Refresh UG.book Page 330 Wednesday, February 17, 2010 12:34 PM Chapter 8 Specifications System Characteristics System Characteristics System Characteristics Scan Triggering Scan Count: Scan Interval: Channel Delay: External Trig Delay: External Trig Jitter: 1 to 50,000 or continuous 0 to 99 hours; 1 ms step size 0 to 60 seconds/channel; 1 ms step size < 300 s; With Monitor On, < 200 ms < 2 ms Alarms Alarm Outputs: 4 TTL compatible.
34970A Refresh UG.
34970A Refresh UG.book Page 332 Wednesday, February 17, 2010 12:34 PM Chapter 8 Specifications System Speed Specifications System Speed Specifications Data out of memory [3][4] (FETCh of 50K readings) 34970A 34972A over GPIB over RS232 over USB over LAN or memory readings/sec readings/sec readings/sec readings/sec Readings 800 600 55K 120K Readings with timestamp 450 320 35K 60K Readings with all format options ON.
34970A Refresh UG.
34970A Refresh UG.book Page 334 Wednesday, February 17, 2010 12:34 PM Chapter 8 Specifications Module Specifications Module Specifications 34905A, 34906A RF Multiplexer General Number of Channels Open/Close Speed 34905A 34906A Dual 1x4 50 Dual 1x4 75 60/s Maximum Input Voltage (dc, AC rms) 42 V Current (dc, AC rms) 0.7 A Power (W, VA) 20 W DC Characteristics Offset Voltage [1] < 6 V Initial Closed Channel R[1] < 0.
34970A Refresh UG.
34970A Refresh UG.book Page 336 Wednesday, February 17, 2010 12:34 PM Chapter 8 Specifications Module Specifications Module Specifications 34907A Digital Input/Output Port 1, 2: Vin(L): Vin (H): Vout(L): Vout(H) Vin(H) Max: Alarming: Speed Latency Read/Write Speed: 8 Bit, input or output, non-isolated < 0.8V (TTL) > 2.0V (TTL) < 0.8V @ Iout = -400 mA > 2.
34970A Refresh UG.book Page 337 Wednesday, February 17, 2010 12:34 PM Chapter 8 Specifications Product and Module Dimensions Product and Module Dimensions 103.6 mm 254.4 mm 374.0 mm 4 88.5 mm 212.6 mm 348.3 mm Module TOP 315.6 91.9 All dimensions are shown in millimeters.
34970A Refresh UG.book Page 338 Wednesday, February 17, 2010 12:34 PM Chapter 8 Specifications To Calculate Total Measurement Error To Calculate Total Measurement Error Each specification includes correction factors which account for errors present due to operational limitations of the internal DMM. This section explains these errors and shows how to apply them to your measurements.
34970A Refresh UG.book Page 339 Wednesday, February 17, 2010 12:34 PM Chapter 8 Specifications To Calculate Total Measurement Error Understanding the “ % of range ” Error The range error compensates for inaccuracies that result from the function and range you select. The range error contributes a constant error, expressed as a percent of range, independent of the input signal level. The following table shows the range error applied to the DMM’s 24-hour DC voltage specification.
34970A Refresh UG.book Page 340 Wednesday, February 17, 2010 12:34 PM Chapter 8 Specifications Interpreting Internal DMM Specifications Interpreting Internal DMM Specifications This section is provided to give you a better understanding of the terminology used and will help you interpret the internal DMM’s specifications. Number of Digits and Overrange The “number of digits” specification is the most fundamental, and sometimes, the most confusing characteristic of a multimeter.
34970A Refresh UG.book Page 341 Wednesday, February 17, 2010 12:34 PM Chapter 8 Specifications Interpreting Internal DMM Specifications Resolution Resolution is the numeric ratio of the maximum displayed value divided by the minimum displayed value on a selected range. Resolution is often expressed in percent, parts-per-million (ppm), counts, or bits. For example, a 6½-digit multimeter with 20% overrange capability can display a measurement with up to 1,200,000 counts of resolution.
34970A Refresh UG.book Page 342 Wednesday, February 17, 2010 12:34 PM Chapter 8 Specifications Interpreting Internal DMM Specifications 24-Hour Accuracy The 24-hour accuracy specification indicates the internal DMM’s relative accuracy over its full measurement range for short time intervals and within a stable environment. Short-term accuracy is usually specified for a 24-hour period and for a ±1 °C temperature range.
34970A Refresh UG.book Page 343 Wednesday, February 17, 2010 12:34 PM Chapter 8 Specifications Configuring for Highest Accuracy Measurements Configuring for Highest Accuracy Measurements The measurement configurations shown below assume that the internal DMM is in its Factory Reset state. It is also assumed that manual ranging is enabled to ensure proper full scale range selection.
34970A Refresh UG.
34970A Refresh UG.book Page 343 Wednesday, February 17, 2010 12:34 PM Index If you have questions relating to the operation of the 34970A/ 34972A, call 1-800-452-4844 in the United States, or contact your nearest Agilent Technologies Sales Office.
34970A Refresh UG.
34970A Refresh UG.
34970A Refresh UG.
70A Refresh UG.
34970A Refresh UG.
34970A Refresh UG.
34970A Refresh UG.book Page 350 Wednesday, February 17, 2010 12:34 PM Index Index pasting, channel configuration, 32 PCL, 120, 264 vs.
34970A Refresh UG.book Page 351 Wednesday, February 17, 2010 12:34 PM Index alpha (a), 127 connections, 28 conversion accuracy, 265 measurement tutorial, 266 measurement units, 123 supported types, 28, 123 RTS/CTS flow mode (RS-232), 185 rubber bumpers, removing, 37 S safety notices 3 Sample (*) annunciator, 8 sample programs C and C++, 248 Excel 7.
34970A Refresh UG.
34970A Refresh UG.book Page 353 Wednesday, February 17, 2010 12:34 PM Index switch contact resistance, 319 switch life, 319 switch types form C (SPDT), 73 matrix, 72 multiplexer, 71, 298 switching, errors, 301 syntax, SCPI conventions, 89 system cabling, 67, 255 system clock factory setting, 166 setting the, 29, 166 SYSTem:ERRor? command, 216 SYSTem:PRESet command, 197 totalizer ac vs.
34970A Refresh UG.
