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National Instruments NI PXI-7831R User Manual - Digital I/o

Manual is about: Reconfigurable I/O

Summary of NI PXI-7831R

  • Page 1

    Reconfigurable i/o ni pxi-7831r user manual reconfigurable i/o devices for pxi/compactpci bus computers ni pxi-7831r user manual april 2003 edition part number 370489a-01.

  • Page 2

    Support worldwide technical support and product information ni.Com national instruments corporate headquarters 11500 north mopac expressway austin, texas 78759-3504 usa tel: 512 683 0100 worldwide offices australia 61 2 9672 8846, austria 43 0 662 45 79 90 0, belgium 32 0 2 757 00 20, brazil 55 11 3...

  • Page 3: Important Information

    Important information warranty the ni pxi-7831r 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 defec...

  • Page 4: Compliance

    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 industri...

  • Page 5: Contents

    © national instruments corporation v ni pxi-7831r user manual contents about this manual conventions ...................................................................................................................Vii reconfigurable i/o documentation...................................................

  • Page 6

    Contents ni pxi-7831r user manual vi ni.Com differential connections for ground-referenced signal sources ... 2-8 differential connections for nonreferenced or floating signal sources ................................................................. 2-9 single-ended connection considerations ..........

  • Page 7: About This Manual

    © national instruments corporation vii ni pxi-7831r user manual about this manual this manual describes the electrical and mechanical aspects of the national instruments pxi-7831r device and contains information concerning its operation and programming. The ni pxi-7831r device is a reconfigurable i/...

  • Page 8: Related Documentation

    About this manual ni pxi-7831r user manual viii ni.Com programs, subprograms, subroutines, device names, functions, operations, variables, filenames and extensions, and code excerpts. Reconfigurable i/o documentation the ni pxi-7831r user manual is one piece of the documentation set for your rio sys...

  • Page 9: Introduction

    © national instruments corporation 1-1 ni pxi-7831r user manual 1 introduction this chapter describes the ni pxi-7831r, describes the concept of the reconfigurable i/o (rio) device, lists what you need to get started, describes the optional software and optional equipment, explains how to unpack the...

  • Page 10: Using Pxi With Compactpci

    Chapter 1 introduction ni pxi-7831r user manual 1-2 ni.Com the pxi chassis has the real-time system integration (rtsi) bus to easily synchronize several measurement functions to a common trigger or timing event. The rtsi bus is implemented on the pxi trigger bus on the pxi backplane. The rtsi bus ca...

  • Page 11: What You Need to Get Started

    Chapter 1 introduction © national instruments corporation 1-3 ni pxi-7831r user manual what you need to get started this section contains two lists that detail what you need to get started using the ni pxi-7831r with windows 2000/xp or the rt module. Getting started with windows 2000/xp to set up an...

  • Page 12

    Chapter 1 introduction ni pxi-7831r user manual 1-4 ni.Com ❑ the following documents are included on the ni device drivers cd and are also available at ni.Com/manuals (optional): – labview fpga module release notes – labview fpga module user manual – where to start with the ni pxi-7831r ❑ the labvie...

  • Page 13

    Chapter 1 introduction © national instruments corporation 1-5 ni pxi-7831r user manual ❑ the following documents are included on the ni device drivers cd and are also available at ni.Com/manuals (optional): – labview fpga module release notes – labview fpga module user manual – labview real-time mod...

  • Page 14

    Chapter 1 introduction ni pxi-7831r user manual 1-6 ni.Com user-defined i/o resources with the rio device, you can define both the combination of i/o resources and the i/o resources themselves. You can also create new building blocks on top of fixed i/o resources. For example, one application might ...

  • Page 15

    Chapter 1 introduction © national instruments corporation 1-7 ni pxi-7831r user manual the connectivity between the bus interface and the fixed i/o, including any timing, triggering, processing, and custom i/o required by the application. Timing, triggering, processing, and custom i/o is provided by...

  • Page 16: Software Development

    Chapter 1 introduction ni pxi-7831r user manual 1-8 ni.Com figure 1-3. Fpga logic use in an application with higher-level functions the fpga is volatile and does not retain the vi when it is powered off. Therefore, the vi must be reloaded every time power is turned on. The vi comes from onboard flas...

  • Page 17

    Chapter 1 introduction © national instruments corporation 1-9 ni pxi-7831r user manual fpga module the fpga module enables you to use labview to create vis that run on the rio device, which contains a reconfigurable fpga. The fpga module includes a new function palette, which contains functions that...

  • Page 18: Custom Cabling

    Chapter 1 introduction ni pxi-7831r user manual 1-10 ni.Com refer to appendix b, connecting i/o signals , for more information on using these cables and accessories to connect i/o signals to the pxi-7831r. For the most up-to-date cabling options, refer to ni.Com/catalog or call the sales office near...

  • Page 19: Unpacking

    Chapter 1 introduction © national instruments corporation 1-11 ni pxi-7831r user manual shc68-nt-s (ni part #189041-02) connects to the ni pxi-7831r vhdci connectors on one end of the cable. The other end of the cable is not terminated. This cable ships with a wire list identifying which wire corres...

  • Page 20

    Chapter 1 introduction ni pxi-7831r user manual 1-12 ni.Com do not substitute parts or modify the ni pxi-7831r except as described in this document. Use the ni pxi-7831r only with the chassis, modules, accessories, and cables specified in the installation instructions. You must have all covers and f...

  • Page 21

    Chapter 1 introduction © national instruments corporation 1-13 ni pxi-7831r user manual standard impulse withstand voltage levels that commonly occur in electrical distribution systems. The following is a description of installation categories: • installation category i is for measurements performed...

  • Page 22: Hardware Overview

    © national instruments corporation 2-1 ni pxi-7831r user manual 2 hardware overview of the ni pxi-7831r this chapter presents an overview of the hardware functions and i/o connectors on the ni pxi-7831r. Figure 2-1 shows a block diagram for the ni pxi-7831r, and figure 2-2 shows the parts locator di...

  • Page 23: Analog Input

    Chapter 2 hardware overview of the ni pxi-7831r ni pxi-7831r user manual 2-2 ni.Com figure 2-2. Parts locator diagram for the ni pxi-7831r analog input the ni pxi-7831r has eight independent, 16-bit ai channels that can be simultaneously sampled or sampled at different rates. The input mode is softw...

  • Page 24

    Chapter 2 hardware overview of the ni pxi-7831r © national instruments corporation 2-3 ni pxi-7831r user manual input modes the ni pxi-7831r input mode is software configurable. The input channels support three input modes—differential (diff) input, referenced single-ended (rse) input, and nonrefere...

  • Page 25

    Chapter 2 hardware overview of the ni pxi-7831r ni pxi-7831r user manual 2-4 ni.Com connecting analog input signals the ai signals for the ni pxi-7831r are ai+, ai–, aignd, and aisense. The ai+ and ai– signals are tied to the eight ai channels of the ni pxi-7831r. For all input modes, the ai+ signal...

  • Page 26: Types of Signal Sources

    Chapter 2 hardware overview of the ni pxi-7831r © national instruments corporation 2-5 ni pxi-7831r user manual figure 2-3. Ni pxi-7831r instrumentation amplifier the instrumentation amplifier applies common-mode voltage rejection and presents high input impedance to the ai signals connected to the ...

  • Page 27: Input Modes

    Chapter 2 hardware overview of the ni pxi-7831r ni pxi-7831r user manual 2-6 ni.Com floating signal sources a floating signal source is in no way connected to the building ground system but instead has an isolated ground-reference point. Some examples of floating signal sources are outputs of transf...

  • Page 28

    Chapter 2 hardware overview of the ni pxi-7831r © national instruments corporation 2-7 ni pxi-7831r user manual figure 2-4. Summary of analog input connections + – + – v 1 ai i> aisense aignd i> + – + – v 1 ai i> aisense aignd i> see text for information on bias resistors. + – + – v 1 ai i> aignd i>...

  • Page 29

    Chapter 2 hardware overview of the ni pxi-7831r ni pxi-7831r user manual 2-8 ni.Com differential connection considerations (diff input mode) in diff input mode, the ni pxi-7831r measures the difference between the positive and negative inputs. Diff input mode is ideal for measuring ground-referenced...

  • Page 30

    Chapter 2 hardware overview of the ni pxi-7831r © national instruments corporation 2-9 ni pxi-7831r user manual figure 2-5. Differential input connections for ground-referenced signals with this connection type, the instrumentation amplifier rejects both the common-mode noise in the signal and the g...

  • Page 31

    Chapter 2 hardware overview of the ni pxi-7831r ni pxi-7831r user manual 2-10 ni.Com figure 2-6. Differential input connections for nonreferenced signals figure 2-6 shows two bias resistors connected in parallel with the signal leads of a floating signal source. If you do not use the resistors and t...

  • Page 32

    Chapter 2 hardware overview of the ni pxi-7831r © national instruments corporation 2-11 ni pxi-7831r user manual the source, other than the very high-input impedance of the instrumentation amplifier. You can fully balance the signal path by connecting another resistor of the same value between the p...

  • Page 33

    Chapter 2 hardware overview of the ni pxi-7831r ni pxi-7831r user manual 2-12 ni.Com the ni pxi-7831r provides the reference ground point for the external signal. The nrse input mode is used for ground-referenced signal sources; in this case, the external signal supplies its own reference ground poi...

  • Page 34

    Chapter 2 hardware overview of the ni pxi-7831r © national instruments corporation 2-13 ni pxi-7831r user manual amplifier, and the signal local ground reference is connected to the negative input of the instrumentation amplifier. The ground point of the signal should, therefore, be connected to ais...

  • Page 35: Analog Output

    Chapter 2 hardware overview of the ni pxi-7831r ni pxi-7831r user manual 2-14 ni.Com common-mode signals as long as v+ in and v– in (input signals) are both within their specified input ranges. Refer to appendix a, specifications , for more information about input ranges. Analog output the ni pxi-78...

  • Page 36: Digital I/o

    Chapter 2 hardware overview of the ni pxi-7831r © national instruments corporation 2-15 ni pxi-7831r user manual figure 2-9. Analog output connections digital i/o the ni pxi-7831r has 96 bidirectional dio lines that can be individually configured for either input or output. When the system powers on...

  • Page 37

    Chapter 2 hardware overview of the ni pxi-7831r ni pxi-7831r user manual 2-16 ni.Com devices. Because the ni pxi-7831r digital outputs provide a nominal output swing of 0 to 3.3 v (3.3 v ttl), the ni pxi-7831r dio lines cannot drive 5 v cmos logic levels. To interface to 5 v cmos devices, you must p...

  • Page 38

    Chapter 2 hardware overview of the ni pxi-7831r © national instruments corporation 2-17 ni pxi-7831r user manual figure 2-10 shows signal connections for three typical dio applications. Figure 2-10. Example digital i/o connections figure 2-10 shows dio configured for digital input and dio configured...

  • Page 39: Pxi Trigger Bus

    Chapter 2 hardware overview of the ni pxi-7831r ni pxi-7831r user manual 2-18 ni.Com edge-sensitive or high-frequency digital signals on the dio lines that are paired with power or ground. Because the dio lines that are twisted with other dio lines can couple noise onto each other, these lines shoul...

  • Page 40: Pxi Local Bus

    Chapter 2 hardware overview of the ni pxi-7831r © national instruments corporation 2-19 ni pxi-7831r user manual caution do not drive the same pxi trigger bus line on the same pxi bus segment with the ni pxi-7831r and another device simultaneously. Such signal driving can damage both devices. Ni is ...

  • Page 41: Switch Settings

    Chapter 2 hardware overview of the ni pxi-7831r ni pxi-7831r user manual 2-20 ni.Com other peripheral slots and results in very precise trigger timing signals. For example, an ni pxi-7831r in slot 2 can send out an independent trigger signal to each device plugged into slots using the pxi/lblstar. E...

  • Page 42: Power Connections

    Chapter 2 hardware overview of the ni pxi-7831r © national instruments corporation 2-21 ni pxi-7831r user manual flash memory, repeat the procedure above but return switch 1 to the off position in step 3. Note when the ni pxi-7831r is powered on with switch 1 in the on position, the analog circuitry...

  • Page 43

    Chapter 2 hardware overview of the ni pxi-7831r ni pxi-7831r user manual 2-22 ni.Com through areas with large magnetic fields or high electromagnetic interference. • route signals to the device carefully. Keep cabling away from noise sources. The most common noise source in a pxi daq system is the v...

  • Page 44: Calibration

    © national instruments corporation 3-1 ni pxi-7831r user manual 3 calibration calibration refers to the process of minimizing measurement and output voltage errors. On the ni pxi-7831r, these errors are corrected in the analog circuitry by onboard calibration dacs (caldacs). Because calibration is h...

  • Page 45: External Calibration

    Chapter 3 calibration ni pxi-7831r user manual 3-2 ni.Com onboard voltage reference. The offset and gain errors in the analog circuitry are calibrated out by adjusting the caldacs to minimize these errors. Immediately after internal calibration, the only significant residual calibration error should...

  • Page 46: Specifications

    © national instruments corporation a-1 ni pxi-7831r user manual a specifications this appendix lists the specifications of the ni pxi-7831r. These specifications are typical at 25 °c unless otherwise noted. Analog input input characteristics number of channels ............................... 8 input...

  • Page 47

    Appendix a specifications ni pxi-7831r user manual a-2 ni.Com overvoltage protection ...........................±42 v data transfers ..........................................Interrupts, programmed i/o accuracy information dc transfer characteristics inl.................................................

  • Page 48

    Appendix a specifications © national instruments corporation a-3 ni pxi-7831r user manual settling time crosstalk................................................. –80 db, dc to 100 khz analog output output characteristics number of channels ............................... 8 single-ended, voltage out...

  • Page 49

    Appendix a specifications ni pxi-7831r user manual a-4 ni.Com dc transfer characteristics inl..........................................................±0.5 lsb typ, ±4.0 lsb max dnl ........................................................±0.5 lsb typ, ±1 lsb max monotonicity ...........................

  • Page 50

    Appendix a specifications © national instruments corporation a-5 ni pxi-7831r user manual digital i/o number of channels ni pxi-7831r................................. 96 input/output compatibility ......................................... Ttl digital logic levels maximum output current power-on stat...

  • Page 51

    Appendix a specifications ni pxi-7831r user manual a-6 ni.Com timebase accuracy with onboard base clock .................±100 ppm phase locked to pxi 10 mhz clock.......................±350 ps jitter, 300 ps skew (max) calibration recommended warm-up time.................15 minutes calibration inter...

  • Page 52

    Appendix a specifications © national instruments corporation a-7 ni pxi-7831r user manual physical dimensions (not including connectors) .................... 16.0 by 10.0 cm (6.3 by 3.9 in.) i/o connectors ni pxi-7831r................................. Three 68-pin female high-density vhdci type maxi...

  • Page 53

    Appendix a specifications ni pxi-7831r user manual a-8 ni.Com electromagnetic compatibility emissions................................................En 55011 class a at 10 m fcc part 15a above 1 ghz immunity ................................................En 61326-1:1997 + a2:2001, table 1 emc/emi ....

  • Page 54: Connecting I/o Signals

    © national instruments corporation b-1 ni pxi-7831r user manual b connecting i/o signals this appendix describes how to make input and output signal connections to the ni pxi-7831r i/o connectors. The ni pxi-7831r has two dio connectors with 40 dio lines per connector, and one mio connector with eig...

  • Page 55

    Appendix b connecting i/o signals ni pxi-7831r user manual b-2 ni.Com figure b-1. Ni pxi-7831r connector locations figure b-2 shows the i/o connector pin assignments for the i/o connectors on the ni pxi-7831r. The dio connector pin assignment applies to connectors on the ni pxi-7831r. The mio connec...

  • Page 56

    Appendix b connecting i/o signals © national instruments corporation b-3 ni pxi-7831r user manual figure b-2. Ni pxi-7831r i/o connector pin assignments to access the signals on the i/o connectors, you must connect a cable from the i/o connector to a signal accessory. Plug the small vhdci connector ...

  • Page 57

    Appendix b connecting i/o signals ni pxi-7831r user manual b-4 ni.Com . Caution connections that exceed any of the maximum ratings of input or output signals on the ni pxi-7831r can damage the ni pxi-7831r and the computer. Maximum input ratings for each signal are given in the protection column of ...

  • Page 58

    Appendix b connecting i/o signals © national instruments corporation b-5 ni pxi-7831r user manual connecting to 5b and ssr signal conditioning ni provides cables that allow you to connect signals from the ni pxi-7831r directly to 5b backplanes for analog signal conditioning and ssr backplanes for di...

  • Page 59

    Appendix b connecting i/o signals ni pxi-7831r user manual b-6 ni.Com the nsc68-262650 cable is designed to connect the signals on the ni pxi-7831r mio connector directly to 5b and ssr backplanes. This cable has a 68-pin male vhdci connector on one end that plugs into the ni pxi-7831r mio connector....

  • Page 60

    Appendix b connecting i/o signals © national instruments corporation b-7 ni pxi-7831r user manual , figure b-3. Connector pinouts when using nsc68-262650 cable the nsc68-5050 cable is designed to connect the signals on the ni pxi-7831r dio connectors directly to ssr backplanes for digital signal con...

  • Page 61

    Appendix b connecting i/o signals ni pxi-7831r user manual b-8 ni.Com lines on the nsc68-5050 cable header. In this case, you only have access to the channels that exist on both the ssr backplane and the nsc68-5050 cable header you are using. Figure b-4 shows the connector pinouts when using the nsc...

  • Page 62: Using The Scb-68

    © national instruments corporation c-1 ni pxi-7831r user manual c using the scb-68 shielded connector block this appendix describes how to connect input and output signals to the ni pxi-7831r with the scb-68 shielded connector block. The scb-68 has 68 screw terminals for i/o signal connections. To u...

  • Page 63: Quick Reference Label

    Appendix c using the scb-68 shielded connector block ni pxi-7831r user manual c-2 ni.Com quick reference label figure c-2 shows the pinout that appears on the scb-68 quick reference label that ships with the ni pxi-7831r. Figure c-2. Scb-68 quick reference label for the ni pxi-7831r s1 nc = no conne...

  • Page 64: Technical Support and

    © national instruments corporation d-1 ni pxi-7831r user manual d technical support and professional services 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 followi...

  • Page 65

    Appendix d technical support and professional services ni pxi-7831r user manual d-2 ni.Com • 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 ne...

  • Page 66: Glossary

    © national instruments corporation g-1 ni pxi-7831r user manual glossary symbol prefix 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. ≥ greater than or equal to. Less than. ≤ less than or equal to. – negati...

  • Page 67

    Glossary ni pxi-7831r user manual g-2 © national instruments corporation square root of. +5v +5 vdc source signal. A a amperes. A/d analog-to-digital. Ac alternating current. Adc analog-to-digital converter—an electronic device, often an integrated circuit, that converts an analog voltage to a digit...

  • Page 68

    Glossary © national instruments corporation g-3 ni pxi-7831r user manual c c celsius. Caldac calibration dac. Ch channel—pin or wire lead to which you apply or from which you read the analog or digital signal. Analog signals can be single-ended or differential. For digital signals, you group channel...

  • Page 69

    Glossary ni pxi-7831r user manual g-4 © national instruments corporation dio digital input/output. Dio i > digital input/output channel signal. Dma direct memory access—a method by which data can be transferred to/from computer memory from/to a device or memory on the bus while the processor does so...

  • Page 70

    Glossary © national instruments corporation g-5 ni pxi-7831r user manual 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. Inl relative accuracy. L labview laboratory virtua...

  • Page 71

    Glossary ni pxi-7831r user manual g-6 © national instruments corporation n noise an undesirable electrical signal—noise comes from external sources such as the ac power line, motors, generators, transformers, fluorescent lights, crt displays, computers, electrical storms, welders, radio transmitters...

  • Page 72

    Glossary © national instruments corporation g-7 ni pxi-7831r user manual r ram random-access memory—the generic term for the read/write memory that is used in computers. Ram allows bits and bytes to be written to it as well as read from. Various types of ram are dram, edo ram, sram, and vram. Resolu...

  • Page 73

    Glossary ni pxi-7831r user manual g-8 © national instruments corporation t thd total harmonic distortion—the ratio of the total rms signal due to harmonic distortion to the overall rms signal, in decibel or a percentage. Thermocouple a temperature sensor created by joining two dissimilar metals. The...