Computer-Based Instruments NI 5620 User Manual Digitizer for PXI ™ NI 5620 User Manual June 2001 Edition Part Number 322949B-01
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Important Information Warranty The NI 5620 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 FCC/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 Mark compliance scheme.
Conventions The following conventions are used 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, DBIO<3..0>. » The » symbol leads you through nested menu items and dialog box options to a final action. The sequence File»Page Setup»Options directs you to pull down the File menu, select the Page Setup item, and select Options from the last dialog box.
Contents Chapter 1 Taking Measurements with the NI 5620 Installing the Software and Hardware ...........................................................................1-1 Acquiring Data with Your NI 5620 ...............................................................................1-2 Programmatically Controlling Your NI 5620..................................................1-2 Safety Information .........................................................................................................
1 Taking Measurements with the NI 5620 Thank you for buying a National Instruments (NI) 5620 digitizer. This chapter provides information on installing, connecting signals to, and acquiring data from the NI 5620.
Chapter 1 Taking Measurements with the NI 5620 Acquiring Data with Your NI 5620 You can acquire data programmatically either by writing an application for your NI 5620 or using one of the examples that ships with NI-SCOPE. Programmatically Controlling Your NI 5620 To help you get started programming your NI 5620, the software comes with examples that you can use or modify.
Chapter 1 Taking Measurements with the NI 5620 Caution Do not operate the device in an explosive atmosphere or where there may be flammable gases or fumes. The device can only be operated at or below pollution degree 2, as stated in Appendix A, Specifications. Pollution is foreign matter, solid, liquid, or gas that may produce a reduction of dielectric strength or surface resistivity.
2 Hardware Overview This chapter provides an overview of the features and functionality of the NI 5620. How the NI 5620 Works A signal follows this path through the NI 5620 to your host computer: 1. The signal enters the NI 5620 through the analog front panel connector, INPUT. To find more about the front panel, see the Connecting Signals section later in this chapter. 2. The signal is filtered and conditioned. Gain and dither are applied to the signal.
Chapter 2 Hardware Overview Connecting Signals Figure 2-2 shows the NI 5620 front panel, which contains three connectors—two SMA connectors and an SMB connector. One of the SMA connectors, INPUT, is for attaching the analog input signal you wish to measure. The second SMA connector, REF CLK IN, is a 50 Ω,10 MHz, AC-coupled reference input. The SMB connector, PFI1, is for external digital triggers. 5620 64 MS/s Digitizer INPUT 50 +20 dBm MAX REF CLK IN 50 +16 dBm MAX PFI 1 Figure 2-2.
Chapter 2 Hardware Overview Conditioning the Signal—Impedance, Dither, Gain, and AC Coupling To minimize distortion, signals receive a minimal amount of conditioning. There is one set gain, and all signals are AC coupled, meaning that the NI 5620 rejects any DC portion of a signal. The NI 5620 also has a set input impedance of 50 Ω and applies dither to the configurable signal. Input Impedance The input impedance of the NI 5620 is 50 Ω.
Chapter 2 Hardware Overview Incorporating the DDC You may optionally route the data through the DDC before storing it in onboard memory. The DDC is a digital signal processing (DSP) chip, the Intersil HSP50214B. The first stage uses a digital quadrature mixer that shifts a signal to baseband from any frequency within the digitizer’s range. The next stage decimates (reduces the sample rate) by an integer from 4 to 16384.
Chapter 2 Hardware Overview Block Diagram This block diagram is intended for advanced users. An explanation of some of these features follows. Digital Downconverter Dither Analog Input (INPUT) + Filter Data Path Logic ADC Onboard Memory MITE (PXI Interface) P X I PLL Phase Detector Voltage Controlled Oscillator TIO (Timing and Control) 10 MHz Reference Input (REF CLK IN) CalDAC Trigger and Clock Routing PXI Trigger External Trigger EXT TRIG (PFI) CLK 10 Figure 2-3.
Chapter 2 Hardware Overview acquisition clock in a free-running state, in which the acquisition clock is not synchronized to any external reference. The voltage controlled crystal oscillator (VCXO) is a 64 MHz clock. The trigger and clock routing area directs clock signals and triggers. The TIO is the timing engine used for the NI 5620. The MITE is the PXI bus interface. The MITE provides high-speed direct memory access (DMA) transfers from the NI 5620 to the host computer’s memory.
Chapter 2 1 Trigger Hardware Overview 2 3 500 ns Acquisition In Progress Buffer 1 1 2 2 = Trigger Not Accepted (Pretrigger Points Not Acquired) = Trigger Not Accepted (500 ns Dead Time) 3= Trigger Not Accepted (Acquisition in Progress) = Trigger Accepted Figure 2-4. Multiple-Record Acquisition Timing Diagram Triggering You can externally trigger the NI 5620 through the digital line, PFI1. You can also use software to trigger it. Figure 2-5 shows the different trigger sources.
Chapter 2 Hardware Overview Synchronizing Multiple PXI Devices The NI 5620 uses a PLL to synchronize the 64 MHz sample clock to a 10 MHz reference clock. You can either supply the reference clock through the SMA connector (REF CLK IN) on the front panel or use the system reference clock on the PXI backplane.
A Specifications This appendix lists the specifications of the NI 5620. These specifications are typical at 25 °C unless otherwise specified. General Specifications Number of channels ............................... 1 Resolution .............................................. 14 bits Max sample rate ..................................... 64 MS/s (also integer divisions of 64 MS/s) Onboard memory Using DDC (complex data) ............ 8 MS Not using DDC ...............................
Appendix A Specifications VSWR 0.1 to 25 MHz..................................< 1.5:1 25 to 32 MHz...................................< 3:1 Dither (can be disabled) Frequency range ..............................15 kHz to 3 MHz Frequency Internal Sample Clock Frequency ........................................64 MHz / n, where 1 ≤ n ≤ 232 Accuracy..........................................
Appendix A Specifications 0 -10 -20 -30 dB -40 -50 -60 -70 0 10 30 20 40 50 60 Frequency (MHz) 70 90 80 100 Figure A-1. Frequency Response from 5 to 100 MHz Phase Group delay variation (5 to 25 MHz)......................................... 9 nspk-to-pk Group delay variation (0.5 to 30 MHz)...................................... 26 nspk-to-pk DDC Decimation rate with installed software ................................... 32 to 4096 DDC tuning resolution ........................... 0.
Appendix A Specifications Triggering Modes .....................................................Immediate, software, digital Sources....................................................PFI 1, RTSI<0..7>, PXI star Export .....................................................RTSI<0..7>, PFI 1 Slope .......................................................Rising, falling Pretrigger depth ......................................Up to 16 MS Posttrigger depth.....................................
Appendix A Specifications Environmental Specifications Calibration interval ................................ 1 year Warm-up time ........................................ 10 minutes Operating environment Ambient temperature ...................... 0 to 50 °C Humidity ......................................... 10 to 90%, noncondensing Storage environment Storage temperature ........................ –20 to 70 °C Humidity ......................................... 5 to 95%, noncondensing Maximum altitude .......
Appendix A Specifications Electromagnetic Compatibility CE, C-Tick, and FCC Part 15 (Class A) compliant Electrical emissions ................................EN 55011 Class A at 10 m FCC Part 15A above 1 GHz Electrical immunity ................................Evaluated to EN 61326:1997/A1:1998, Table 1 For full EMC compliance, you must operate this device with shielded cabling. In addition, all covers and filler panels must be installed.
Technical Support Resources B Web Support National Instruments Web support is your first stop for help in solving installation, configuration, and application problems and questions. Online problem-solving and diagnostic resources include frequently asked questions, knowledge bases, product-specific troubleshooting wizards, manuals, drivers, software updates, and more. Web support is available through the Technical Support section of ni.com. NI Developer Zone The NI Developer Zone at ni.
Appendix B Technical Support Resources Worldwide Support National Instruments has offices located around the world to help address your support needs. You can access our branch office Web sites from the Worldwide Offices section of ni.com. Branch office Web sites provide up-to-date contact information, support phone numbers, e-mail addresses, and current events.
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 % percent + positive of, or plus – negative of, or minus / per ° degree ± plus or minus Ω ohm < less than A A amperes A/D analog-to-digital AC alternating current © National Instruments Corporation G-1 NI 5620 User Manual
Glossary AC coupled allowing the transmission of AC signals while blocking DC signals ADC analog-to-digital converter—an electronic device, often an integrated circuit, that converts an analog voltage to a digital number ADC resolution the resolution of the ADC, which is measured in bits. An ADC with 16 bits has a higher resolution, and thus a higher degree of accuracy, than a 12-bit ADC.
Glossary CMRR common-mode rejection ratio—a measure of an instrument’s ability to reject interference from a common-mode signal, usually expressed in decibels (dB) coupling the manner in which a signal is connected from one location to another D data path logic a signal router dB decibel—the unit for expressing a logarithmic measure of the ratio of two signal levels: dB=20log10 V1/V2, for signals in volts dBm Decibels with reference to 1 mW, the standard unit of power level used in RF and microwav
Glossary drivers software that controls a specific hardware instrument DSP digital signal processor E EEPROM electrically erasable programmable read-only memory—ROM that can be erased with an electrical signal and reprogrammed F FFT fast Fourier transform filtering a type of signal conditioning that allows you to remove unwanted signals or frequency components from the signal you are trying to measure G gain the factor by which a signal is amplified, sometimes expressed in decibels H hardware
Glossary input bias current the current that flows into the inputs of a circuit input impedance the measured resistance and capacitance between the input terminals of a circuit instrument driver a set of high-level software functions that controls a specific plug-in DAQ board. Instrument drivers are available in several forms, ranging from a function callable language to a virtual instrument (VI) in LabVIEW.
Glossary N noise an undesirable electrical signal—Noise comes from external sources such as the AC power line, motors, generators, transformers, fluorescent lights, soldering irons, CRT displays, computers, electrical storms, welders, radio transmitters, and internal sources such as semiconductors, resistors, and capacitors. Noise corrupts signals you are trying to send or receive. O Ohm’s Law (R=V/I)—the relationship of voltage to current in a resistance onboard memory the device memory.
Glossary random interleaved sampling method of increasing sample rate by repetitively sampling a repeated waveform real-time sampling sampling that occurs immediately record length the size of a chunk (or record) of data that can be or has been acquired by a device resolution the smallest signal increment that can be detected by a measurement system. Resolution can be expressed in bits, in proportions, or in percent of full scale.
Glossary T temperature coefficient the percentage that a measurement will vary according to temperature. See also thermal drift. thermal drift measurements that change as the temperature varies thermal EMFs thermal electromotive forces—voltages generated at the junctions of dissimilar metals that are functions of temperature. Also called thermoelectric potentials. thermoelectric potentials See thermal EMFs. TIO timing input/output. The engine used for timing and control.
Glossary W waveform shape the shape the magnitude of a signal creates over time working voltage the highest voltage that should be applied to a product in normal use, normally well under the breakdown voltage for safety margin © National Instruments Corporation G-9 NI 5620 User Manual
Index A dead time, in multiple-record acquisitions, 2-7 digital downconverter. See DDC (digital downconverter).
Index programmatically controlling the NI 5620, 1-2 PXI devices, multiple, synchronizing, 2-8 signal path from NI 5620 to host computer, 2-1 storing data in memory, 2-4 synchronizing multiple PXI devices, 2-8 triggering, 2-7 R REF CLK IN connector, 2-2, 2-8 I incorporating DDC, 2-4 input impedance, 2-3 input specifications, A-1 to A-2 installing software and hardware, 1-1 S safety information, 1-2 to 1-3 safety specifications, A-5 signal conditioning AC coupling, 2-3 dither, 2-3 gain, 2-3 input impedan
Index V system integration, by National Instruments, B-1 System Reference Clock, PXI, 2-9 voltage, maximum working, A-5 voltage controlled crystal oscillator (VCXO), 2-6 T W technical support resources, B-1 to B-2 TIO (timing engine), 2-6 trigger and clock routing area, 2-6 triggering digital trigger sources (figure), 2-7 overview, 2-7 specifications, A-4 © National Instruments Corporation Web support from National Instruments, B-1 Worldwide technical support, B-2 I-3 NI 5620 User Manual
