DAQ SCB-68 68-Pin Shielded Connector Block User Manual SCB-68 Shielded Connector Block User Manual December 2002 Edition Part Number 320745B-01
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Important Information Warranty The SCB-68 is warranted against defects in materials and workmanship for a period of one year from the date of shipment, as evidenced by receipts or other documentation. National Instruments will, at its option, repair or replace equipment that proves to be defective during the warranty period. This warranty includes parts and labor.
Compliance FFCC/Canada Radio Frequency Interference Compliance Determining FCC Class The Federal Communications Commission (FCC) has rules to protect wireless communications from interference. The FCC places digital electronics into two classes. These classes are known as Class A (for use in industrial-commercial locations only) or Class B (for use in residential or commercial locations). Depending on where it is operated, this product could be subject to restrictions in the FCC rules.
Canadian Department of Communications This Class B digital apparatus meets all requirements of the Canadian Interference-Causing Equipment Regulations. Cet appareil numérique de la classe B respecte toutes les exigences du Règlement sur le matériel brouilleur du Canada. Compliance to EU Directives Readers in the European Union (EU) must refer to the Manufacturer’s Declaration of Conformity (DoC) for information* pertaining to the CE Marking compliance scheme.
Contents About This Manual Conventions ...................................................................................................................xi NI Documentation..........................................................................................................xii Chapter 1 Introduction What You Need to Get Started ......................................................................................1-1 Quick Reference Label ................................................................
Contents Single-Ended Connection Considerations ...................................................... 3-8 Single-Ended Connections for Floating Signal Sources (RSE Input Mode).......................................................................... 3-9 Single-Ended Connections for Grounded Signal Sources (NRSE Input Mode)....................................................................... 3-9 Connecting Analog Output Signals .............................................................................
Contents Selecting a Resistor .........................................................................................5-17 Adding Components........................................................................................5-18 Single-Ended Inputs..........................................................................5-18 Differential Inputs .............................................................................5-18 Attenuating Voltage .........................................................
About This Manual This manual describes the SCB-68 and explains how to use the connector block with National Instruments data acquisition (DAQ) devices. Conventions The following conventions appear in this manual: <> Angle brackets that contain numbers separated by an ellipsis represent a range of values associated with a bit or signal name—for example, DIO<3..0>. » The » symbol leads you through nested menu items and dialog box options to a final action.
About This Manual NI Documentation For more information about using the SCB-68 with DAQ devices, refer to the following resources: • DAQ device user manuals, at ni.com/manuals • NI Developer Zone, at ni.com/zone SCB-68 Shielded Connector Block User Manual xii ni.
1 Introduction The SCB-68 is a shielded I/O connector block with 68 screw terminals for easy signal connection to a National Instruments 68- or 100-pin DAQ device. The SCB-68 features a general breadboard area for custom circuitry and sockets for interchanging electrical components. These sockets or component pads allow RC filtering, 4 to 20 mA current sensing, open thermocouple detection, and voltage attenuation.
Chapter 1 Introduction ❑ The following items, if you are adding components (optional): – Soldering iron and solder – Resistors – Capacitors Quick Reference Label A quick reference label for E Series devices is included in this kit. Quick reference labels for some other devices ship with the DAQ device itself. These labels show the switch configurations and define the screw terminal pinouts for compatible DAQ devices.
Chapter 1 Introduction Table 1-1.
Chapter 1 Introduction Table 1-1.
Chapter 1 Introduction 1 2 3 9 10 5 4 6 8 7 1 2 3 Quick Reference Label Cover 68-Pin Connector Screws 4 5 6 7 Lock Washers 8 Strain-Relief Bars Shielding Screws 9 Strain-Relief Screws 68-Pin I/O Connector 10 Circuit Card Assembly Base Figure 1-1. SCB-68 Parts Locator Diagram Installing Cables The following sections describe how to cable one or more SCB-68 connector blocks to a DAQ device using 68-pin or 100-pin cables.
Chapter 1 Introduction Figure 1-2 shows how to use a 68-pin cable to connect the SCB-68 to a 68-pin DAQ device. 1 5 1 2 3 4 68-Pin Cable Assembly 68-Pin DAQ Device 68-Pin I/O Connector 3 4 5 2 68-Pin I/O Connector SCB-68 Connector Block Figure 1-2. Connecting a 68-Pin DAQ Device to an SCB-68 Using 100-Pin Cables You can use the SH1006868 cable assembly to connect two SCB-68 connector blocks to a 100-pin DAQ device.
Chapter 1 Introduction 3 1 2 5 1 2 3 SCB-68 Connector Blocks 68-Pin I/O Connectors SH1006868 Cable Assembly 4 5 4 100-Pin DAQ Device 100-Pin I/O Connector Figure 1-3. Connecting a 100-Pin DAQ Device to Two SCB-68 Connector Blocks When you attach two SCB-68 devices to the SH1006868 cable, one of the SCB-68 connector blocks has a full 68-pin I/O connector pinout, and the other SCB-68 connector block has an extended AI or extended digital pinout.
Chapter 1 Introduction ACH8 ACH1 AIGND ACH10 ACH3 AIGND ACH4 AIGND ACH13 ACH6 AIGND ACH15 DAC0OUT1 DAC1OUT1 EXTREF3 DIO4 DGND DIO1 DIO6 DGND +5V DGND DGND PFI0/TRIG1 PFI1/TRIG2 DGND +5V DGND PFI5/UPDATE* PFI6/WFTRIG DGND PFI9/GPCTR0_GATE GPCTR0_OUT FREQ_OUT 34 33 32 31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 68 67 66 65 64 63 62 61 60 59 58 57 56 55 54 53 52 51 50 49 48 47 46 45 44 43 42 41 40 39 38 37 36 35 ACH0 AIGND ACH9 ACH2 AIGND ACH11 AISENSE ACH12 ACH5 AI
Chapter 1 Introduction Figure 1-5 shows the pin assignments for the extended AI connector. This pinout shows the other 68-pin connector when you use the SH1006868 cable assembly with an NI 6031E, NI 6033E, or NI 6071E.
Chapter 1 Introduction Figure 1-6 shows the pin assignments for the extended digital connector. This pinout shows the other 68-pin connector when you use the SH1006868 cable assembly with an NI 6025E or the NI 6021E (AT-MIO-16DE-10) for ISA.
Chapter 1 Introduction Configuring the SCB-68 For instructions about using Measurement & Automation Explorer (MAX) to configure the SCB-68 as an accessory for a DAQ device, complete the following steps: 1. Navigate to MAX by selecting Start»Programs»National Instruments»Measurement&Automation. 2. Select Help»Help Topics»NI-DAQ in MAX. 3. Select DAQ Devices»Configuring DAQ Devices»Configuring DAQ Devices»Accessory in the Measurement & Automation Explorer Help for MAX.
Chapter 1 Introduction • Pollution Degree 3 means that conductive pollution occurs, or dry, nonconductive pollution occurs that becomes conductive due to condensation. Clean the SCB-68 with a soft nonmetallic brush. Make sure that the SCB-68 is completely dry and free from contaminants before returning it to service. You must insulate signal connections for the maximum voltage for which the SCB-68 is rated. Do not exceed the maximum ratings for the SCB-68.
Chapter 1 Introduction installation, and equipment for industrial use, such as stationary motors with a permanent connection to the building/fixed installation. • Installation Category IV is for measurements performed at the source of the low-voltage (<1,000 V) installation. Examples of Installation Category IV are electric meters, and measurements on primary overcurrent protection devices and ripple-control units. Below is a diagram of a sample installation.
Parts Locator and Wiring Guide 2 This chapter explains how to connect signals to the SCB-68. The following cautions contain important safety information concerning hazardous voltages and terminal blocks. Cautions Keep away from live circuits. Do not remove equipment covers or shields unless you are trained to do so. If signal wires are connected to the SCB-68, dangerous voltages may exist even when the equipment is powered off.
Chapter 2 Parts Locator and Wiring Guide RC16(B) R27(C) R8(F) RC6(E) R9(G) RC17(D) R28(A) RC18(B) R29(C) RC7(E) C5 RC19(D) R10(F) R30(A) RC20(B) R31(C) R12(F) RC8(E) R13(G) RC21(D) R32(A) RC22(B) R11(G) C3 R38 R14(F) RC9(E) R33(C) R15(G) RC23(D) R34(A) RC10(E) R35(C) R17(G) RC25(D) R36(A) RC26(B) R18(F) RC11(E) R37(C) R19(G) RC27(D) RC2 R2 RC3 R3 © 1 2 3 4 5 6 7 Pads R20 and R21 Switches S3, S4, and S5 68-Pin I/O Connector Fuse (0.
Chapter 2 Parts Locator and Wiring Guide To connect signals to the SCB-68, complete the following steps while referring to Figure 1-1, SCB-68 Parts Locator Diagram, and to Figure 2-1. 1. Disconnect the 68-pin cable from the SCB-68, if it is connected. 2. Remove the shielding screws on either side of the top cover with a Phillips-head number 1 screwdriver. You can now open the box. 3. Configure the switches and other options relative to the types of signals you are using. 4.
Chapter 2 Parts Locator and Wiring Guide Table 2-1.
Chapter 2 Parts Locator and Wiring Guide Table 2-1.
3 Connecting Signals This chapter describes the types of signal sources that you use when configuring the channels and making signal connections to the SCB-68, describes input modes, and discusses noise considerations to help you acquire accurate signals. Connecting Analog Input Signals The following sections describe how to connect signal sources for single-ended or differential (DIFF) input mode.
Chapter 3 Connecting Signals Signal Source Type Input Floating Signal Source (Not Connected to Building Ground) Grounded Signal Source Examples: • Ungrounded thermocouples • Signal conditioning with Isolated outputs • Battery devices Examples: • Plug-in instruments with nonisolated outputs ACH(+) + V 1 – Differential (DIFF) CommonMode Voltage ACH(+) + ACH(–) + V 1 – – R + – CommonMode Voltage AIGND ACH(–) + – + – AIGND Refer to the Using Bias Resistors section for information on bias
Chapter 3 Connecting Signals Nonreferenced or Floating Signal Sources A floating signal source is a signal source that is not connected in any way to the building ground system, but has an isolated ground-reference point. Instruments or devices with isolated outputs are considered floating signal sources, and they have high-impedance paths to ground. Some examples of floating signal sources are outputs for thermocouples, transformers, battery-powered devices, optical isolators, and isolation amplifiers.
Chapter 3 Connecting Signals Ground-Referenced Signal Sources A grounded signal source is connected in some way to the building system ground; therefore, the signal source is already connected to a common ground point with respect to the DAQ device (assuming that the host computer is plugged into the same power system). Nonisolated outputs of instruments and devices that plug into the building power system fall into this category.
Chapter 3 Connecting Signals Analog Input Channel Configuration Diagram for ACH and ACH). Any signal conditioning circuitry requiring a ground reference should be built in the custom breadboard area using AISENSE as the ground reference instead of building the circuitry in the open component positions. Referencing the signal to AIGND can cause inaccurate measurements resulting from an incorrect ground reference.
Chapter 3 Connecting Signals Differential Connections for Ground-Referenced Signal Sources Figure 3-2 shows how to connect a ground-referenced signal source to a channel on the DAQ device configured in DIFF input mode.
Chapter 3 Connecting Signals Differential Connections for Nonreferenced or Floating Signal Sources Figure 3-3 shows how to connect a floating signal source to a channel on the DAQ device configured in DIFF input mode. ACH+ or ACH + Floating Signal Source Instrumentation Amplifier + PGIA Vs + – – Measured Voltage Vm – ACH– or ACH Bias Resistor (see text) AISENSE* AIGND I/O Connector Measurement Device Configured in DIFF Input Mode *AISENSE is not present on all devices. Figure 3-3.
Chapter 3 Connecting Signals Common-mode rejection might be improved by using another bias resistor between ACH+ or ACH, and AIGND. This connection creates a slight measurement error caused by the voltage divider formed with the output impedance of the floating source, but it also gives a more balanced input for better common-mode rejection.
Chapter 3 Connecting Signals Single-Ended Connections for Floating Signal Sources (RSE Input Mode) Figure 3-4 shows how to connect a floating signal source to a channel on the DAQ device configured for RSE input mode. ACH Floating Signal Source + Instrumentation Amplifier PGIA + Vs – – + Measured Voltage Vm AISENSE* – AIGND I/O Connector Measurement Device Configured in RSE Input Mode *Not all devices support RSE input mode. Figure 3-4.
Chapter 3 Connecting Signals Figure 3-5 shows how to connect a grounded signal source to a channel on the DAQ device configured for NRSE input mode. GroundReferenced Signal Source CommonMode Noise and Ground Potential ACH + Instrumentation Amplifier + Vs PGIA – AISENSE* + – AIGND Vcm + Measured Voltage Vm – – I/O Connector Measurement Device Configured in NRSE Input Mode *Not all devices support NRSE input mode. Figure 3-5.
Chapter 3 Connecting Signals Figure 3-6 shows how to make AO connections and the external reference connection to the SCB-68 and the DAQ device. EXTREF External Reference Signal (optional) + + DAC0OUT Vref VOUT 0 – Load – AOGND – Load VOUT 1 DAC1OUT + SCB-68 Figure 3-6. Connecting AO Signals Connecting Digital Signals When using the SCB-68 with a 68-pin or 100-pin DAQ device, the DIO signals are DIO<0..7> and DGND. DIO<0..
Chapter 3 Connecting Signals +5 V LED DIO<4..7> TTL Signal DIO<0..3> +5 V Switch DGND I/O Connector SCB-68 Figure 3-7. Digital I/O Connections Connecting Timing Signals If you are using a 68-pin or 100-pin DAQ device, all external control over device timing is routed through the programmable function input (PFI) lines <0..9>. These PFI lines are bidirectional; as outputs they are not programmable and reflect the state of many DAQ, waveform generation, and general-purpose timing signals.
Chapter 3 Connecting Signals All digital timing connections are referenced to DGND. Figure 3-8 demonstrates how to connect two external timing signals to the PFI pins of a DAQ device. PFI0 PFI2 PFI0 Source PFI2 Source DGND I/O Connector SCB-68 Figure 3-8. Timing I/O Connections Noise Considerations Environmental noise can seriously affect the measurement accuracy of your application if you do not take proper care when running signal wires between signal sources and the device.
Chapter 3 Connecting Signals ACH+ and ACH– inputs are twisted together and then covered with a shield. You then connect this shield at only one point to the signal source ground. This kind of connection is required for signals traveling through areas with large magnetic fields or high electromagnetic interference. • Route signals to the device carefully. Keep cabling away from noise sources. A common noise source in DAQ applications is the computer monitor.
4 Using Thermocouples This chapter describes how to take thermocouple measurements using the SCB-68. A thermocouple is created when two dissimilar metals touch, and the contact produces a small voltage that changes as a function of temperature. By measuring the voltage of a thermocouple, you can determine temperature using a nonlinear equation that is unique to each thermocouple type.
Chapter 4 Using Thermocouples The maximum voltage level thermocouples generate is typically only a few millivolts. Therefore, you should use a DAQ device with high gain for best resolution. You can measure thermocouples in either differential or single-ended configuration. The differential configuration has better noise immunity, but the single-ended configurations have twice as many inputs. The DAQ device must have a ground reference, because thermocouples are floating signal sources.
Chapter 4 Using Thermocouples Temperature Sensor S5 S4 S3 Signal Conditioning Circuitry Power (On) S1 S2 Figure 4-1. Single-Ended Switch Configuration For differential operation, connect differential analog channel 0 to the temperature sensor by switching S5 and S4 to the up position, as shown in Figure 4-2. Temperature Sensor S5 S4 S3 Signal Conditioning Circuitry Power (On) S1 S2 Figure 4-2.
5 Adding Components for Special Functions This chapter describes how to condition signals by adding components to the open component locations of the SCB-68. To add components to these locations, the DAQ device must support switch configurations 2, 3, or 4 in Table 2-1, Switch Configurations and Affected Signals. Caution Add components at your own risk.
Chapter 5 Adding Components for Special Functions You can create virtual channels in MAX to map your voltage ranges to the type of transducer that you are using or to create a custom scale. Channel Pad Configurations When you use the SCB-68 with a 68-pin or 100-pin DAQ device, you can use the component pads on the SCB-68 to condition 16 AI channels, two AO channels, and PFI0/TRIG1. Conditioning Analog Input Channels Figure 5-1 illustrates the AI channel configuration.
Chapter 5 Adding Components for Special Functions Table 5-1. Component Location for Analog Input Channels in DIFF Input Mode (Continued) Channel A B C D E F G ACH4 R30 RC20 RC21 R31 RC8 R12 R13 ACH5 R32 RC22 RC23 R33 RC9 R14 R15 ACH6 R34 RC24 RC25 R35 RC10 R16 R17 ACH7 R36 RC26 RC27 R37 RC11 R18 R19 Conditioning Analog Output Channels Figure 5-2 illustrates the generic AO channel pad configuration, and Table 5-2 describes the AO component locations and labels.
Chapter 5 Adding Components for Special Functions R3 DAC0OUT + RC3 – C AOGND Figure 5-3. Analog Output Channel Configuration Diagram for DAC0OUT Conditioning PFI0/TRIG1 Figure 5-4 illustrates the digital input channel configuration, and Figure 5-5 shows the digital input channel configuration for PFI0/TRIG1. PFI0/TRIG1 (R1) 11 (RC1) 44 DGND Figure 5-4. Digital Input Channel Configuration Diagram R0 PFI0/TRIG1 + RC1 – C DGND Figure 5-5.
Chapter 5 Adding Components for Special Functions Accuracy and Resolution Considerations When you measure voltage to subsequently measure current, take the following steps to maximize measurement accuracy: 1. Refer to the accuracy tables in Appendix A, Specifications, of the DAQ device user manual at ni.com/manuals. 2. Use Equation 5-1 to determine the code width, which is the smallest signal change that a system can detect. 3.
Chapter 5 Adding Components for Special Functions Differential Open Thermocouple Detection Use position A to connect a high-value resistor between the positive input and +5V. Leave the jumpers in place (positions F and G) for each channel used. Single-Ended Open Thermocouple Detection Use position A for one channel and C for the next channel when you connect a high-value resistor between the positive input and +5V. Leave the jumpers at positions F and G in place for each channel used.
Chapter 5 Adding Components for Special Functions Thermocouple wire error is the result of inconsistencies in the thermocouple manufacturing process. These inconsistencies, or nonhomogeneities, are the result of defects or impurities in the thermocouple wire. The errors vary widely depending upon the thermocouple type and even the gauge of wire used, but an error of ±2 °C is typical. For more information on thermocouple wire errors and more specific data, consult the thermocouple manufacturer.
Adding Components for Special Functions Gain Chapter 5 Passband Stopband fc Log Frequency Gain Figure 5-6. Transfer Function Attenuation for an Ideal Filter Passband Stopband Transition Region fc Log Frequency Figure 5-7. Transfer Function Attenuation for a Real Filter The cut-off frequency, fc, is defined as the frequency beyond which the gain drops 3 dB. Figure 5-6 shows how an ideal filter causes the gain to drop to zero for all frequencies greater than fc.
Chapter 5 Adding Components for Special Functions Volts (V) ringing in the signal as the higher frequency components of the signal are delayed. Time (t) Figure 5-8. Square Wave Input Signal Volts (V) Figures 5-9 and 5-10 show the difference in response to a square wave between an ideal and a real filter, respectively. Time (t) Figure 5-9.
Adding Components for Special Functions Volts (V) Chapter 5 Time (t) Figure 5-10. Response of a Real Filter to a Square Wave Input Signal One-Pole Lowpass RC Filter Figure 5-11 shows the transfer function of a simple series circuit consisting of a resistor (R) and capacitor (C) when the voltage across R is assumed to be the output voltage (Vm). C Vin R Vm Figure 5-11.
Chapter 5 Adding Components for Special Functions Use Equation 5-3 to design a lowpass filter for a simple resistor and capacitor circuit, where the values of the resistor and capacitor alone determine fc. In this equation, G is the DC gain and s represents the frequency domain. Selecting Components To determine the value of the components in the circuit, fix R (10 kΩ is reasonable) and isolate C from Equation 5-3 as follows: 1 C = --------------2πRfc (5-4) The cut-off frequency in Equation 5-4 is fc.
Chapter 5 Adding Components for Special Functions For any type of lowpass filter, use Equation 5-5 to determine the cut-off frequency (fc). 1 fc = --------------2πRC (5-5) Single-Ended Lowpass Filter To build a single-ended lowpass filter, refer to Figure 5-12. Add the resistor to position B or D, depending on the AI channel you are using. Add the capacitor to position F or G, depending on the AI channel you are using. ACH + Vin CF,G + RB,D Vm – – AIGND Figure 5-12.
Chapter 5 Adding Components for Special Functions Lowpass Filtering Applications Noise filtering and antialiasing are two applications that use lowpass filters. Noise Filtering You can use a lowpass filter to highly attenuate the noise frequency on a measured signal. For example, power lines commonly add a noise frequency of 60 Hz. Adding a filter with fc< 60 Hz at the input of the measurement system causes the noise frequency to fall into the stopband.
Chapter 5 Adding Components for Special Functions To prevent aliasing, remove all signal components with frequencies greater than the Nyquist frequency from input signals before those signals are sampled. Once a data sample is aliased, it is impossible to accurately reconstruct the original signal. To design a lowpass filter that attenuates signal components with a frequency higher than half of the Nyquist frequency, substitute the half Nyquist value for the fc value in Equation 5-6.
Adding Components for Special Functions Volts (V) Chapter 5 Time (t) Figure 5-15. Lowpass Filtering of AO Signals Special Consideration for Digital Trigger Input Signals Volts (V) Lowpass filters can function as debouncing filters to smooth noise on digital trigger input signals, thus enabling the trigger-detection circuitry of the DAQ device to understand the signal as a valid digital trigger. TTL Logic High TTL Logic Low Time (t) Figure 5-16.
Chapter 5 Adding Components for Special Functions Volts (V) Apply a lowpass filter to the signal to remove the high-frequency component for a cleaner digital signal, as Figure 5-17 shows. Time (t) Figure 5-17. Lowpass Filtering of Digital Trigger Input Signals Due to the filter order, the digital trigger input signal is delayed for a specific amount of time before the DAQ device senses the signal at the trigger input.
Chapter 5 Adding Components for Special Functions I + + Transducer Input R – Vm – Figure 5-18. Current-to-Voltage Electrical Circuit The application software must linearly convert voltage back to current.
Chapter 5 Adding Components for Special Functions Adding Components Caution Do not exceed ±10 V at the analog inputs. NI is not liable for any device damage or personal injury resulting from improper connections. You can build a one-resistor circuit for measuring current at the single-ended or differential inputs of the SCB-68.
Chapter 5 Adding Components for Special Functions R1 + Vin + R2 – Vm – Figure 5-19. Attenuating Voltage with a Voltage Divider Theory of Operation The voltage divider splits the input voltage (Vin) between two resistors (R1 and R2), causing the voltage on each resistor to be noticeably lower than Vin.
Chapter 5 Adding Components for Special Functions Selecting Components To set up the resistors, complete the following steps: 1. Select the value for R2 (10 kΩ is recommended). 2. Use Equation 5-12 to calculate the value for R1.
Chapter 5 ACH + Vin Adding Components for Special Functions RF,G + RB,D Vm – – AIGND Figure 5-20. SCB-68 Circuit Diagram for SE Input Attenuation Install resistors in positions B and F, or positions D and G, depending on the channel you are using on the SCB-68.
Chapter 5 Adding Components for Special Functions Analog Output and Digital Input Attenuators To build a two-resistor circuit for attenuating voltages at the DAC0OUT, DAC1OUT, and TRIG1 pins on the SCB-68, refer to the pad positions in Figure 5-22. ACH + Vin CF + RE – ACH Vm – Figure 5-22.
Chapter 5 Adding Components for Special Functions R1 + + Vin Input Impedance R2 – – Figure 5-23. Input Impedance Electrical Circuit Zin is the new input impedance. Refer to Appendix A, Specifications, in the device user manuals at ni.com/manuals for the input impedance.
Chapter 5 Adding Components for Special Functions Special Considerations for Digital Inputs If you use the Vin voltage of Figure 5-20 to feed TTL signals, you must calculate Vin so that the voltage drop on R2 does not exceed 5 V. Caution A voltage drop exceeding 5 V on R2 can damage the internal circuitry of the DAQ device. NI is not liable for any device damage or personal injury resulting from improper use of the SCB-68 and the DAQ device. SCB-68 Shielded Connector Block User Manual 5-24 ni.
A Specifications This appendix lists the SCB-68 specifications. These ratings are typical at 25 °C unless otherwise stated. Analog Input Number of channels 68-pin DAQ devices ....................... Eight differential, 16 single-ended 100-pin DAQ devices ..................... 32 differential, 64 single-ended Temperature sensor Accuracy ......................................... ±1.0 °C over a 0 to 110 °C range Output .............................................
Chapter A Specifications Voltage rating .........................................250 V Nominal resistance .................................0.195 Ω Physical Box dimensions (including box feet)......19.5 by 15.2 by 4.5 cm (7.7 by 6.0 by 1.8 in.) I/O connectors.........................................One 68-pin male SCSI connector Screw terminals ......................................68 Wire gauge..............................................≤26 AWG Resistor sockets ......................................0.
Chapter A Specifications Safety The SCB-68 meets the requirements of the following standards for safety and electrical equipment for measurement, control, and laboratory use: Note • IEC 61010-1, EN 61010-1 • UL 3111-1 • CAN/CSA C22.2 No. 1010.1 For UL and other safety certifications, refer to the product label or to ni.com. Electromagnetic Compatibility Emissions ............................................... EN 55011 Class A at 10 m FCC Part 15A above 1 GHz Immunity.............................
Quick Reference Labels B This appendix shows the pinouts that appear on the quick reference labels for the DAQ devices that are compatible with the SCB-68.
Chapter B Quick Reference Labels SCB-68 Quick Reference Label E SERIES DEVICES NATIONAL INSTRUMENTS P/N 182509B-01 FACTORY DEFAULT SETTING 0 S1 S2 S5 S4 S3 * TEMP.
Chapter B Quick Reference Labels SCB-68 Quick Reference Label NI 670X DEVICES NATIONAL INSTRUMENTS PIN # SIGNAL 68 AGND0/AGND16 34 VCH0 PIN # SIGNAL 67 ICH16* 12 VCH14 PIN # SIGNAL 1 +5V OUTPUT 33 AGND1/AGND17 46 AGND14/AGND30 35 DGND 66 VCH1 13 ICH29* 2 DIO0 32 ICH17* 47 VCH13 36 DGND 3 DIO1 65 AGND2/AGND18 14 AGND13AGND29 31 VCH2 48 ICH28* 37 DGND 64 ICH18* 15 VCH12 4 DIO2 38 RFU 30 AGND3/AGND19 49 AGND12/AGND28 63 VCH3 16 29 ICH19* 50 AGND11/AGND
Chapter B Quick Reference Labels SCB-68 Quick Reference Label NI 671X/673X DEVICES NATIONAL INSTRUMENTS PIN # FACTORY DEFAULT SETTING S1 S2 S5 S4 S3 * TEMP.
Chapter B Quick Reference Labels SCB-68 Quick Reference Label S SERIES DEVICES NATIONAL INSTRUMENTS PIN # P/N 182509B-01 FACTORY DEFAULT SETTING S1 S2 S5 S4 S3 SIGNAL 68 ACH0 34 ACH0- PIN # SIGNAL PIN # SIGNAL 67 ACH0GND 12 DGND 1 FREQ_OUT 33 ACH1+ 46 SCANCLK 35 DGND 66 ACH1- 13 DGND 2 GPCTR0_OUT 32 ACH1GND 47 DIO3 36 DGND 65 ACH2+ 14 +5V 3 PFI9/GPCTR0_GATE 31 ACH2- 48 DIO7 37 PFI8/GPCTR0_SOURCE 64 ACH2GND 15 DGND 4 DGND 30 ACH3+ 49 DIO2 38 PFI7/ST
Chapter B Quick Reference Labels SCB-68 Quick Reference Label NI 660X DEVICES NATIONAL INSTRUMENTS PIN# If using an NI 660X device with an optional SCB-68 shielded connector block accessory, affix this label to the inside of the SCB-68 and set the switches as shown below. P/N 185974A-01 SET SWITCHES AS FOLLOWS FOR NI 660X DEVICES.
Chapter B Quick Reference Labels SCB-68 Quick Reference Label NI 653X DEVICES NATIONAL INSTRUMENTS PIN# SIGNAL If using an NI 653X with an optional SCB-68 shielded connector block accessory, affix this label to the inside of the SCB-68 and set the switches as shown below. P/N 185754A-01 Rev.
Chapter B Quick Reference Labels SCB-68 Quick Reference Label 1 NI 7811R/7831R DEVICES NATIONAL INSTRUMENTS PIN# 1 THE MIO COLUMN CORRESPONDS TO THE MIO CONNECTOR ON THE NI 7831R, AND THE DIO COLUMN CORRESPONDS TO THE DIO CONNECTORS ON THE NI 7811R / 7831R.
C Fuse and Power One of the +5 V lines from the DAQ device (pin 8) is protected by an 800 mA fuse. Pin 14 is also +5 V, but it is not fuse-protected on the SCB-68. Shorting pin 14 to ground blows the fuse, which is usually socketed. If the SBC-68 does not work when you turn on the DAQ device, first check the switch settings, then check both the 800 mA fuse on the SCB-68 and the output fuse (if any) on the DAQ device. Before replacing any fuses, check for short circuits from power to ground.
D SCB-68 Circuit Diagrams This appendix contains illustrations of circuit diagrams for the SCB-68. XF1 (Clip) 800 mA 5x20 mm +5V Screw Terminal +5V (I/O Pin 8) ACC Not Powered (NC) S1 ACC Powered R20 (Optional) R21 +5 V DGND (I/O Pin 7) AIGND (I/O Pin 56) DGND Screw Terminal AIGND Screw Terminal Non-MIO (NC) S2 MIO C1 C2 (10 µF) (0.1 µF) C4 C6 (10 µF) (0.1 µF) AI AI Non-MIO (NC) S3 MIO AI Figure D-1.
Chapter D SCB-68 Circuit Diagrams +5V R22 R4 CJC Not Used ACH0 Screw Terminal RC12 + AIGND User Configurable +5V ACH0 (I/O Pin 68) S5 CJC Used C3 (0.1 µF) Q1 R38 AI C5 (1 µF) +5V AI R23 R5 ACH8 (I/O Pin 34) RSE CJC or Non-MIO S4 DIFF CJC ACH8 Screw Terminal + RC13 AI AIGND User Configurable Figure D-2. Cold-Junction Compensation Circuitry R1 PFI0/TRIG1 (I/O Pin 11) PFI0/TRIG1 Screw Terminal RC1 DGND (I/O Pin 44) DGND Screw Terminal Figure D-3.
Chapter D SCB-68 Circuit Diagrams R3 DAC0OUT (I/O Pin 22) DAC0OUT Screw Terminal RC3 AOGND (I/O Pin 55) AOGND Screw Terminal R2 DAC1OUT (I/O Pin 21) DAC1OUT Screw Terminal RC2 AOGND (I/O Pin 54) AOGND Screw Terminal Figure D-4.
E Soldering and Desoldering on the SCB-68 Some applications discussed here require you to make modifications to the SCB-68, usually in the form of adding components to the printed circuit device. To solder and desolder components on the SCB-68, refer to Figure 2-1, SCB-68 Printed Circuit Diagram, and to Figure E-1, and complete the following steps to remove the SCB-68 from its box.
Chapter E Soldering and Desoldering on the SCB-68 1. Disconnect the 68-pin cable from the SCB-68 if it is connected. 2. Remove the shielding screws on either side of the top cover with a Phillips-head number 1 screwdriver. You can now open the box. 3. Loosen the strain-relief screws with a Phillips-head number 2 screwdriver. 4. Remove the signal wires from screw terminals. 5. Remove the device-mount screws and the 68-pin connector screws. 6. Tilt the SCB-68 up and pull it out.
Technical Support and Professional Services F Visit the following sections of the National Instruments Web site at ni.com for technical support and professional services: • Support—Online technical support resources include the following: – Self-Help Resources—For immediate answers and solutions, visit our extensive library of technical support resources available in English, Japanese, and Spanish at ni.com/support.
Chapter F Technical Support and Professional Services • Calibration Certificate—If your product supports calibration, you can obtain the calibration certificate for your product at ni.com/calibration. If you searched ni.com and could not find the answers you need, contact your local office or NI corporate headquarters. Phone numbers for our worldwide offices are listed at the front of this manual. You also can visit the Worldwide Offices section of ni.
Glossary Prefix Meanings Value p- pico 10 –12 n- nano- 10 –9 µ- micro- 10 – 6 m- milli- 10 –3 k- kilo- 10 3 M- mega- 10 6 G- giga- 10 9 Numbers/Symbols ° degrees > greater than ≤ less than or equal to ≥ greater than or equal to < less than – negative of, or minus Ω ohms / per % percent ± plus or minus + positive of, or plus © National Instruments Corporation G-1 SCB-68 Shielded Connector Block User Manual
Glossary square root of +5V +5 VDC source signal A A amperes A/D analog-to-digital AC alternating current ACH analog input channel signal ADC analog-to-digital converter—an electronic device, often an integrated circuit, that converts an analog voltage to a digital number AI analog input AIGND analog input ground signal AISENSE analog input sense signal AO analog output AOGND analog output ground signal ASIC Application-Specific Integrated Circuit—a proprietary semiconductor componen
Glossary cm centimeter cold-junction compensation CJC—an artificial reference level that compensates for ambient temperature variations in thermocouple measurement circuits CompactPCI refers to the core specification defined by the PCI Industrial Computer Manufacturer’s Group (PICMG) CONVERT* convert signal counter/timer a circuit that counts external pulses or clock pulses (timing) CTR counter D DAC digital-to-analog converter—an electronic device, often an integrated circuit, that converts a
Glossary E EXTREF external reference signal EXTSTROBE external strobe signal EXTTRIG external trigger signal F FREQ_OUT frequency output signal ft feet G gain the factor by which a signal is amplified, often expressed in dB GATE gate signal GPCTR general purpose counter GPCTR0_GATE general purpose counter 0 gate signal GPCTR1_GATE general purpose counter 1 gate signal GPCTR0_OUT general purpose counter 0 output signal GPCTR1_OUT general purpose counter 1 output signal GPCTR0_SOURCE
Glossary I I/O input/output—the transfer of data to/from a computer system involving communications channels, operator interface devices, and/or data acquisition and control interfaces IOH current, output high IOL current, output low L lowpass filter a filter that passes low frequencies LSB least significant bit M m meter MB megabytes of memory MIO multifunction I/O N NC normally closed, or not connected NI-DAQ NI driver software for DAQ hardware noise an undesirable electrical signal—
Glossary Nyquist frequency a frequency that is half of the sampling frequency O OUT output pin—a counter output pin where the counter can generate various TTL pulse waveforms P PCI Peripheral Component Interconnect—a high-performance expansion bus architecture originally developed by Intel to replace ISA and EISA. It is achieving widespread acceptance as a standard for PCs and work-stations; it offers a theoretical maximum transfer rate of 132 MB/s.
Glossary PXI PCI eXtensions for Instrumentation—an open specification that builds off the CompactPCI specification by adding instrumentation-specific features R range the maximum and minimum parameters between which a device operates with a specified set of characteristics RC filter resistor-capacitor filter resolution the smallest signal increment that can be detected by a measurement system; is expressed in bits, proportions, or percent of full scale RH relative humidity rms root mean square
Glossary T thermocouple a temperature sensor created by joining two dissimilar metals; the junction produces a small voltage as a function of the temperature TRIG trigger signal TTL transistor-transistor logic U unipolar a signal range that is always positive (for example, 0 to +10 V) UPDATE update signal V V volts VDC volts direct current Vin volts in Vm measured voltage Vout volts out Vrms volts, root mean square W waveform multiple voltage readings taken at a specific sampling rat
Index Numbers component locations (table), 5-2 to 5-3 configuration diagram (figure), 5-2 input attenuators, 5-22 to 5-23 lowpass filter considerations, 5-14 specifications, A-1 analog input signal connections, 3-1 to 3-10 differential connections DIFF input mode description, 3-5 ground-referenced signal sources, 3-4, 3-6 nonreferenced or floating signal sources, 3-3, 3-7 to 3-8 ground-referenced signal sources description, 3-4 differential inputs, 3-4, 3-6 single-ended inputs, 3-4 to 3-5, 3-9 to 3-10 inpu
Index SCB-68 E Series I/O Connector pinout (extended digital) (figure), 1-10 SCB-68 E Series I/O Connector pinout (full) (figure), 1-8 quick reference labels (table), 1-2 calibration certificate, F-2 CE compliance specifications, A-3 channel pad configurations, 5-2 to 5-4 analog input channels, 5-2 to 5-3 component locations (table), 5-2 to 5-3 configuration diagram (figure), 5-2 analog output channels, 5-3 to 5-4 component locations (table), 5-3 configuration diagram (figure), 5-3 DAC0OUT configuration di
Index connecting signals, 3-1 to 3-14 analog input signals, 3-1 to 3-10 differential connections DIFF input mode description, 3-5 ground-referenced signal sources, 3-4, 3-6 nonreferenced or floating signal sources, 3-3, 3-7 to 3-8 ground-referenced signal sources description, 3-4 differential inputs, 3-4, 3-6 single-ended inputs, 3-4 to 3-5, 3-9 to 3-10 input modes recommended input modes (figure), 3-2 types of, 3-1 nonreferenced or floating signal sources description, 3-3 differential inputs, 3-3, 3-7 to
Index digital trigger circuitry diagram (figure), D-2 input signals, lowpass filtering, 5-15 to 5-16 documentation conventions used in manual, xi NI documentation, xii selecting resistor, 5-17 theory of operation, 5-16 to 5-17 D DAC0OUT signal component location in DIFF input mode (table), 5-3 configuration diagram (figure), 5-4 DAC1OUT signal component location (table), 5-3 Declaration of Conformity (DoC), F-1 desoldering and soldering, E-1 to E-2 differential connections (DIFF input mode) component loc
Index I analog input channels, 5-14 analog output channels, 5-14 to 5-15 digital trigger input signals, 5-15 to 5-16 square wave input signal entry into filters (figure), 5-9 response of ideal filter (figure), 5-9 response of real filter (figure), 5-10 theory of operation, 5-7 to 5-10 input modes.
Index NI 653X devices (table), B-7 NI 660X devices (table), B-6 NI 670X devices (table), B-3 NI 671X/673X devices (table), B-4 NI 7811R/7831R devices (table), B-8 other devices (table), 1-4 real-time (RT) devices (table), 1-3 S series devices (table), 1-4, B-5 timing I/O (TIO) devices (table), 1-4 nonreferenced or floating signal sources bias resistors, 3-7 description, 3-3 description (figure), 3-2 differential connections, 3-3, 3-7 to 3-8 recommended configuration (figure), 3-2 single-ended connections
Index T safety information, 1-11 to 1-13 specifications, A-1 to A-3 SCB-68 E Series I/O Connector pinout extended AI (figure), 1-9 extended digital (figure), 1-10 full (figure), 1-8 signal connections.
Index special considerations analog input, 5-22 to 5-23 analog output, 5-23 digital inputs, 5-24 theory of operation, 5-19 SCB-68 Shielded Connector Block User Manual I-8 ni.
