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Reconfigurable I/O NI PXI-7831R User Manual

1. Signal Impedance Protection Driver Typeand Input Volts Source Sink Rise Signal Name Type Direction Output On Off mA at V mAat V Time Bias 45V DO AI lt 0 7 gt AI 10 GQ in 42 35 2 nA parallel with 100 pF AI lt 0 7 gt AI 10 GQ in 42 35 2 nA parallel with 100 pF AIGND AO AISENSE AI 10 GQ in 42 35 2 nA parallel with 100 pF lt 0 7 gt AO 1250 Short 5 at 10 5 at 10 10 V us circuit to ground AOGND DGND DO DIO lt 0 15 gt Default DIO 0 5 5 4 at 2 4 5 0 at 0 4 12 ns Connector 0 to 47 0 DIO lt 0 39 gt Connector lt 1 2 gt Slow DIO 0 5 1 9 at 0 4 1 9 at 0 4 75 ns to 47 0 Fast DIO 0 5 16 at 2 4 14 at 0 4 6ns to 47 0 AI Analog Input AO Analog Output DIO Digital Input Output DO Digital Output 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 digital signal conditioning National Instruments Corporation B 5 NI PXI 7831R User Manual Appendix B NI PXI 7831R User Manual Connecting 1 0 Signals The NSC68 262650 cable is designed to connect the signals on the NI PXI 7831R MIO connector directly to 5B and SSR b
2. 1 25 Q max Current drive eed 5 mA Protection niri Short circuit to ground Power on state essen User configurable Dynamic Characteristics Settling time Accuracy Step Size 16 LSB ALSB 2LSB 20 0 V 6 0 us 6 2 us 7 2 us 2 0 V 2 2 us 2 0 us 3 8 us 0 2 V 1 5 us 2 6 us 3 6 us SLEW tate ine esed 10 V us estere qtia tes ee nt 150 DC to 1 MHz Glitch energy at midscale transition 100 mV for 3 us NI PXI 7831R User Manual 4 4 ni com Appendix A Specifications Digital 1 0 Number of channels NEPXI 7831R nests kine eae 96 input output Compatibility eene TTL Digital logic levels Level Min Max Input low voltage 0 0 V 0 8 V Input high voltage Vip 2 0 V 5 5 V Output low voltage VoL 0 4 V where Iour Imax sink Output high voltage 2 4 V where Imax source Maximum output current Driver Type Software Selectable Source Sink Default 5 4 mA 5 0 mA Slow 1 9 mA 1 9 mA Fast 16 mA 14 mA Power on state essent Programmable by line Data transferts irre Interrupts programmed I O Protection 0 5 to 7 0 V eme cemere erus Short circuit up to eight lines may be shorted at a time Reconfigurable FPGA Number o
3. E 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 nonreferenced single ended NRSE input The selected input mode applies to all the input channels Table 2 2 describes the three input modes Table 2 2 Available Input Modes for the NI PXI 7831R Input Mode Description DIFF When the NI PXI 7831R is configured in DIFF input mode each channel uses two AI lines The positive input pin connects to the positive terminal of the onboard instrumentation amplifier and the negative input pin connects to the negative input of the instrumentation amplifier RSE When the NI PXI 7831R is configured in RSE input mode each channel uses only its positive AI pin This pin connects to the positive terminal of the onboard instrumentation amplifier The negative input of the instrumentation amplifier is internally tied to the AI ground AIGND NRSE When the NI PXI 7831R is configured in NRSE input mode each channel uses only its positive AI pin This pin connects to the positive terminal of the onboard instrumentation amplifier The negative input of the instrumentation amplifier on each AI channel is internally connected to the AI sense AISENSE input pin Input Range The NI PXI 7831R AI range is fixed at 10 V National Instruments Corporation 2
4. Channel 0 Load VOUT 0 AOGNDO a 3 x8 Channels NI PXI 7831R Figure 2 9 Analog Output Connections Digital 1 0 The NI PXI 7831R has 96 bidirectional DIO lines that can be individually configured for either input or output When the system powers on the DIO lines are all high impedance To set another power on state you can configure the NI PXI 7831R to automatically load a VI when the system powers on This VI can then set the DIO lines to any desired power on state Connecting Digital 1 0 Signals The DIO signals on the NI PXI 7831R MIO connector are DGND and DIO lt 0 15 gt The DIO signals the NI PXI 7831R DIO connector are DGND and DIO lt 0 39 gt DIO lt 0 n gt are the signals making up the DIO port and DGND is the ground reference signal for the DIO port The NI PXI 7831R has one MIO and two DIO connectors for a total of 96 DIO lines Refer to Figure B 1 NI PXI 7831R Connector Locations and Figure B 2 NI PXI 7831R I O Connector Pin Assignments for the connector locations and the I O connector pin assignments on the NI PXI 7831R The DIO lines on the NI PXI 7831R are TTL compatible When configured as inputs they can receive signals from 5 V TTL 3 3 V LVTTL 5 V CMOS and 3 3 V LVCMOS devices When configured as outputs they can send signals to 5 V TTL 3 3 V LVTTL and 3 3 V LVCMOS National Instruments Corporation 2 15 NI
5. Al lt i Differential DIFF AIGND lt i gt See text for information on bias resistors NOT RECOMMENDED lt gt pm Ov Single Ended Oy eS Ground h Referenced RSE AIGND Ground loop losses Vg are added to measured signal Al lt i gt O AISENSE Single Ended Nonreferenced NRSE AIGND lt i gt VW See text for information on bias resistors National Instruments Corporation Figure 2 4 Summary of Analog Input Connections NI PXI 7831R User Manual Chapter 2 Hardware Overview of the NI PXI 7831R Differential Connection Considerations DIFF Input Mode NI PXI 7831R User Manual 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 signals from other devices When using DIFF input mode the input signal is tied to the positive input of the instrumentation amplifier and its reference signal or return is tied to the negative input of the instrumentation amplifier Use differential input connections for any channel that meets any of the following conditions e The input signal is low level less than 1 V e The leads connecting the signal to the NI PXI 7831R are greater than 3 m 10 ft e Th
6. National Instruments Corporation V NI PXI 7831R User Manual Contents Differential Connections for Ground Referenced Signal Sources 2 8 Differential Connections for Nonreferenced or Floating Signal Sources seen 2 9 Single Ended Connection Considerations sees 2 11 Single Ended Connections for Floating Signal Sources RSE Input Mode sese 2 12 Single Ended Connections for Grounded Signal Sources NRSE Input Mode esee 2 12 Common Mode Signal Rejection Considerations eese 2 13 Analog Output 2 14 Connecting Analog Output Signals essere rennen 2 14 Digital etes 2 15 Connecting Digital I O Signals eese nennen 2 15 PXI Trigger BUS e icone tre eo eg ridi 2 18 PXI Bus 3n a HE a 2 19 Switch Settings tra eei e o o v a e ttp ed re eh 2 20 Power Connections 25 2 rtt t quel eoe Ioue ett Ep 2 21 Field Wiring Considerations een tt edente ipe dete te perta 2 21 Chapter 3 Calibration Loading Calibration Constant essent rennen etre etre 3 1 Internal Calibration dated un e Bethe cae nets 3 1 External eer EHE RODEO irme 3 2 Appendix A Specifications Appendix B Connecting 1 0 Signals Appendix C Using the SCB 68 Shielded Connector Block Appendix D Technical Support and Professional Services Glos
7. DGND 11 45 DIO10 11 45 11 DGND 10 44 DIO9 DIO8 10 44 DIO9 DGND 9 43 Dios DGND 9 43 DIO7 DGND 8 42 DIO7 DGND 8 42 DIO6 DGND 7 41 bios DGND 7 41 005 DGND 6 40 0105 40 DIO4 DGND 5 39 DIO4 DGND 5 39 DGND 4 38 DGND 4 38 002 DGND 3 37 0102 DGND 3 37 DGND 2 36 DIO1 2 36 DGND 1 35 45V 1 35 5 DIO Connector Pin Assignment MIO Connector Pin Assignment Figure B 2 NI PXI 7831R 1 0 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 end of the cable into the appropriate I O connector and connect the other end of the cable to the appropriate signal accessory National Instruments Corporation B 3 NI PXI 7831R User Manual Appendix B Connecting 1 0 Signals Table B 1 1 0 Connector Signal Descriptions Signal Name Reference Direction Description 5V DGND Output 5 VDC Source These pins supply 5 V from the computer power supply using a self resetting 1 A fuse No more than 250 mA should be pulled from a single pin AI lt 0 7 gt AIGND Input Positive Input for Analog Channels 0 through 7 AI 0 72 AIGND Input Negative Input for Analog Channels 0 through 7 AIGND Analog Input Ground These pins are the reference point for single ende
8. 20 0 V 7 5 us 10 3 us 40 us 2 0 2 7 us 4 1 us 5 1 us 0 2 V 1 7 us 2 9 us 3 6 us Crosstal 80 dB DC to 100 kHz Analog Output Output Characteristics Number of channels 8 single ended voltage output Resol tiOr se remet 16 bits 1 in 65 536 Update tite ie eet 1 0 us Max update 1 MS s Typeot ien ete Enhanced R 2R Data transfers nimio Interrupts programmed I O Accuracy Information Absolute Accuracy Nominal Range V of Reading Absolute Accuracy at Positive Full Negative Full Temp Drift Full Scale Scale Scale 24 Hours 1 Year Offset uV mV 10 0 10 0 0 0335 0 0351 2366 0 0005 5 88 Note Accuracies are valid for analog output following an internal calibration Analog output accuracies are listed for operation temperatures within 1 C of internal calibration temperature and 10 C of external or factory calibration temperature Temp Drift applies only if ambient is greater than 10 C of previous external calibration National Instruments Corporation A 3 NI PXI 7831R User Manual Appendix A Specifications DC Transfer Characteristics IN ni Gace ets tere teorie dies 0 5 LSB typ 4 0 LSB max DNE uisi roten 0 5 LSB typ 1 LSB max Monotonicity 16 bits guaranteed Voltage Output Range aunties did 10 V Output coupling DC Output
9. DC DGND DIFF National Instruments Corporation G 3 Glossary Celsius Calibration DAC 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 channels to form ports Ports usually consist of either four or eight digital channels Centimeter Complementary metal oxide semiconductor Common mode rejection ratio a measure of an instrument s ability to reject interference from a common mode signal usually expressed in decibels dB Any voltage present at the instrumentation amplifier inputs with respect to amplifier ground Refers to the core specification defined by the PCI Industrial Computer Manufacturer s Group PICMG Digital to analog Digital to analog converter an electronic device often an integrated circuit that converts a digital number into a corresponding analog voltage or current Data acquisition a system that uses the computer to collect receive and generate electrical signals Decibel the unit for expressing a logarithmic measure of the ratio of two signal levels dB 20log10 V1 V2 for signals in volts Direct current Digital ground signal Differential mode NI PXI 7831R User Manual Glossary DIO DIO lt i gt DMA DNL DO E EEPROM F FPGA FPGA VI glitch NI PXI 7831R User Manual Digital input output Digital input ou
10. NC 01014 19 20 NC 01013 21 22 NC 01012 23 24 NC 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 conditioning This cable has a 68 pin male VHDCI connector on one end that plugs into the NI PXI 7831R DIO connectors The other end of this cable provides two 50 pin female headers Each of these 50 pin headers can be plugged directly into an 8 16 24 or 32 channel SSR backplane for digital signal conditioning One of the 50 pin headers contains DIO lines 0 23 from the NI PXI 7831R DIO connector These lines are mapped to slots 0 23 on an SSR backplane in sequential order The other 50 pin header contains DIO lines 24 39 from the NI PXI 7831R DIO connector These lines are mapped to slots 0 15 on an SSR backplane in sequential order You can connect to an SSR backplane containing a number channels that does not equal the number of National Instruments Corporation B 7 NI PXI 7831R User Manual Appendix B NI PXI 7831R User Manual Connecting 1 0 Signals 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 connect
11. Specifications for more information about input ranges The NI PXI 7831R has eight 16 bit AO channels The bipolar output range is fixed at 10 V Some applications require that the AO channels power on to known voltage levels To set the power on levels you can configure the NI PXI 7831R to automatically load and run your VI when the system powers on This VI can then set the AO channels to the desired voltage levels Data written to the DAC is interpreted in two s complement format Table 2 3 shows the ideal AO voltage generated for a given input code Table 2 3 Ideal Output Voltage and Input Code Mapping Input Code Hex Output Description AO Voltage Two s Complement Full scale range 1 LSB 9 999695 7 Full scale range 2 LSB 9 999390 7FFE Midscale 0 000000 0000 Negative full scale range 9 999695 8001 1 LSB Negative full scale range 10 000000 8000 Any output voltage d E 32 768 Note Ifthe output value for an AO channel is not specifically set by your VI then the AO channel voltage output will be undefined Connecting Analog Output Signals NI PXI 7831R User Manual The AO signals are AO lt 0 7 gt and AOGND lt 0 7 gt are the eight available AO channels AOGND is the ground reference signal for the AO channels Figure 2 9 shows how to make AO connections to the NI PXI 7831R 2 14 ni com Chapter 2 Hardware Overview of the NI PXI 7831R
12. and current events NI PXI 7831R User Manual D 2 ni com Glossary Symbol Prefix Value p pico 10 2 n nano 107 u micro 10 6 m milli 10 3 k kilo 103 M mega 106 G giga 10 Numbers Symbols E Degrees gt Greater than 2 Greater than or equal to lt Less than lt Less than or equal to Negative of or minus Q Ohms Per Percent Plus or minus Positive of or plus National Instruments Corporation G 1 NI PXI 7831R User Manual Glossary r 5V A D AC ADC Al Al lt i gt AIGND AISENSE AO AO lt i gt AOGND ASIC bipolar NI PXI 7831R User Manual Square root of 5 VDC source signal Amperes Analog to digital Alternating current Analog to digital converter an electronic device often an integrated circuit that converts an analog voltage to a digital number Analog input Analog input channel signal Analog input ground signal Analog input sense signal Analog output Analog output channel signal Analog output ground signal Application Specific Integrated Circuit a proprietary semiconductor component designed and manufactured to perform a set of specific functions A signal range that includes both positive and negative values for example 5 to 5 V G 2 National Instruments Corporation CalDAC CH cm CMOS CMRR common mode voltage CompactPCI D A DAC DAQ dB
13. before a VI is loaded into the FPGA Internal Calibration The NI PXI 7831R can measure and correct for almost all of its calibration related errors without any external signal connections This calibration method is referred to as internal calibration NI provides software to perform an internal calibration This internal calibration process which generally takes less than two minutes is the preferred method of assuring accuracy in your application Initiate an internal calibration to minimize the effects of any offset and gain drifts particularly those due to changes in temperature During the internal calibration process the AI and AO channels are compared to the NI PXI 7831R National Instruments Corporation 3 1 NI PXI 7831R User Manual Chapter 3 Calibration 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 be gain error due to time and temperature drift of the onboard voltage reference This error is addressed by external calibration which is discussed in the External Calibration section If you are interested primarily in relative measurements you can ignore a small amount of gain error and self calibration should be sufficient The results of an internal calibration can be stored in the flash memory on the NI PXI 7831R so that th
14. by 10 0 cm 6 3 by 3 9 in connectors NI PXI 7831R eese Three 68 pin female high density VHDCI type Maximum Working Voltage Maximum working voltage refers to the signal voltage plus the common mode voltage Channel to earth esses x12 V Installation Category I Channel to channel x24 V Installation Category I Environmental Operating 40 to 70 C Storage temperature 55 to 85 C Humidity nemen 10 to 90 RH noncondensing Maximum altitude 2 000 meters Pollution Degree indoor use only 2 Safety The NI PXI 7831R devices meet the requirements of the following standards for safety and electrical equipment for measurement control and laboratory use e TEC 61010 1 EN 61010 1 e UL3III 1 e CAN CSA C22 2 No 1010 1 Note For UL and other safety certifications refer to the product label or to ni com National Instruments Corporation A 7 NI PXI 7831R User Manual Appendix A Specifications Electromagnetic Compatibility Emissions eeeeeeeeenenn nnns EN 55011 Class A at 10 FCC Part 15A above 1 GHz Heini 61326 1 1997 2 2001 Table 1 tme CE C Tick and FCC Part 15 Class A Compliant Note For EMC compliance you must operate th
15. meets the following conditions e The input signal is high level 21 V e leads connecting the signal to the NI PXI 7831R are less than 3 m 10 ft e The input signal can share a common reference point with other signals DIFF input connections are recommended for greater signal integrity for any input signal that does not meet the preceding conditions You can configure in software the NI PXI 7831R channels for two different types of single ended connections RSE input mode and NRSE input mode The RSE input mode is used for floating signal sources in this case National Instruments Corporation 2 11 NI PXI 7831R User Manual Chapter 2 Hardware Overview of the NI PXI 7831R 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 point and the NI PXI 7831R should not supply one In single ended input modes more electrostatic and magnetic noise couples into the signal connections than in differential input modes The coupling is the result of differences in the signal path Magnetic coupling is proportional to the area between the two signal conductors Electrical coupling is a function of how much the electric field differs between the two conductors Single Ended Connections for Floating Signal Sources RSE Input Mode Figure 2 7 shows how to connect a floatin
16. to the device The instrumentation amplifier can reject common mode signals as long as V and V input signals are both within their specified input ranges Refer to Appendix A Specifications for more information about input ranges Differential Connections for Nonreferenced or Floating Signal Sources Figure 2 6 shows how to connect a floating signal source to a channel on the NI PXI 7831R configured in DIFF input mode National Instruments Corporation 2 9 NI PXI 7831R User Manual Chapter 2 Hardware Overview of the NI PXI 7831R i Resistors Floating see text Signal Vs Source _ 4 Bias Current Return Paths Connector Bias 1 Instrumentation i Amplifier Measured Loo Voltage 8 Channels DIFF Input Mode Selected NI PXI 7831R User Manual 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 the source is truly floating the source is not likely to remain within the common mode signal range of the instrumentation amplifier and the instrumentation amplifier will saturate causing erroneous readings You must reference the source to AIGND which you can do by connecting the positive side of the signal to the positi
17. use the SCB 68 with the NI PXI 7831R you must configure the SCB 68 as a general purpose connector block Refer to Figure C 1 for the general purpose switch configuration S5 4 3 51 52 Figure 1 General Purpose Switch Configuration for the SCB 68 Terminal Block After configuring the SCB 68 switches you can connect the I O signals to the SCB 68 screw terminals Refer to Appendix B Connecting I O Signals for the connector pin assignments for the NI PXI 7831R After connecting signals to the SCB 68 screw terminals you can connect the SCB 68 to the NI PXI 7831R with the SH68 C68 S shielded cable National Instruments Corporation C 1 NI PXI 7831R User Manual Appendix C Using the SCB 68 Shielded Connector Block 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 SCB 68 Quick Reference Label NATIONAL y INSTRUMENTS 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 NC No Connect SET SWITCHES IN THIS CONFIGURATION TO USE THE SCB 68 WITH THE NI 7811R 7881R AM x NI 7811R 7831R DEVICES MIO AIO AIGNDO DIO12 DIO PIN MIO AIGND1 01013 01014 Alt DIO15 Al2 AOGND7 Al2 AO7 AIGND2 AOGND
18. you to the experts by phone discussion forum or email Training Visitni com custed for self paced tutorials videos and interactive CDs You also can register for instructor led hands on courses at locations around the world e System Integration lIf you have time constraints limited in house technical resources or other project challenges NI Alliance Program members can help To learn more call your local NI office or visit ni com alliance Declaration of Conformity DoC A DoC is our claim of compliance with the Council of the European Communities using the manufacturer s declaration of conformity This system affords the user protection for electronic compatibility EMC and product safety You can obtain the DoC for your product by visiting ni com hardref nsf National Instruments Corporation D 1 NI PXI 7831R User Manual Appendix D Technical Support and Professional Services e 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 com niglobal to access the branch office Web sites which provide up to date contact information support phone numbers email addresses
19. 2 bit quadrature decoders and then reconfigure the RIO device in another application for eight 16 bit event counters In timing and triggering applications the flexible functionality of the RIO device makes it an ideal complement to applications based on the RT module such as control and hardware in the loop HIL simulations For example you can configure the RIO device for a single timed loop in one application and then reconfigure the device in another application for four independent timed loops with separate I O resources National Instruments Corporation 1 5 NI PXI 7831R User Manual Chapter 1 Introduction User Defined 1 0 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 require an event counter that increments when a rising edge appears on any of three digital input lines Another application might require a digital line to be asserted once an analog input exceeds a programmable threshold You can implement these user defined behaviors in the hardware for fast deterministic performance Device Embedded Logic and Processing You can embed logic and processing in the FPGA of the RIO device Typical logic functions include Boolean operations comparisons and basic mathematical operations You can implement multiple functions efficiently in the same design
20. 3 NI PXI 7831R User Manual Chapter 2 Hardware Overview of the NI PXI 7831R Connecting Analog Input Signals The AI signals for the NI PXI 7831R are AI lt 0 7 gt lt 0 7 gt AIGND AISENSE The AI lt 0 7 gt and AI lt 0 7 gt signals are tied to the eight AI channels of the NI PXI 7831R For all input modes the AI lt 0 7 gt signals are connected to the positive input of the instrumentation amplifier on each channel The signal connected to the negative input of the instrumentation amplifier depends on the input mode for which the NI PXI 7831R is configured In differential input mode signals connected to lt 0 7 gt are routed to the negative input of the instrumentation amplifier for each channel In RSE input mode the negative input of the instrumentation amplifier for each channel is internally connected to AIGND In NRSE input mode the AISENSE signal is connected internally to the negative input of the instrumentation amplifier for each channel In DIFF and RSE input modes AISENSE is not used and can be left unconnected UN Caution Exceeding the differential and common mode input ranges distorts the input signals Exceeding the maximum input voltage rating can damage the NI PXI 7831R and the computer NI is not liable for any damage resulting from such signal connections The maximum input voltage ratings are listed in Table B 2 NJ PXI 7831R I O Signal Summary AIGND is a common AI signal that is rou
21. 6 AIGND3 AO6 Al3 AOGND5 Al3 AO5 Al4 AOGND4 Al4 4 AIGND4 AOGND3 AIGND5 Al5 AOGND2 Al5 AO2 Al6 AOGNDO Al6 AO1 AIGND6 AOGNDO AIGND7 AOO Al7 NC 5 4 3 NI PXI 7831R User Manual Al7 AISENSE Figure C 2 SCB 68 Quick Reference Label for the NI PXI 7831R C 2 ni com Technical Support and Professional Services Visit the following sections of the National Instruments Web site at ni com for technical support and professional services e 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 These resources are available for most products at no cost to registered users and include software drivers and updates a KnowledgeBase product manuals step by step troubleshooting wizards conformity documentation example code tutorials and application notes instrument drivers discussion forums a measurement glossary and so on Assisted Support Options Contact NI engineers and other measurement and automation professionals by visiting ni com support Our online system helps you define your question and connects
22. A Specifications Overvoltage protection 42 V Data tette t Interrupts programmed I O Accuracy Information Relative Absolute Accuracy Accuracy Noise Quantization Nominal Range V of Reading Absolute Resolution Accuracy Positive Negative Temp at Full Full Full 24 Offset Single Drift Scale Single Scale Scale Hours 1 Year uV Pt Averaged C xmV Pt Averaged 10 0 10 0 0 0496 0 0507 2542 1779 165 0 0005 7 78 2170 217 Note Accuracies are valid for measurements following an internal calibration Measurement accuracies are listed for operational temperatures within 1 C of internal calibration temperature and 10 C of external or factory calibration temperature Temp drift applies only if ambient is greater than 10 C of previous external calibration DC Transfer Characteristics INE etch ertet No missing codes resolution CMRR DC to 60 2 86 dB Dynamic Characteristics Bandwidth Small signal 3 dB 820 kHz Large signal 1 55 kHz SYSUEM NOISE dieere 1 8 LSBuns NI PXI 7831R User Manual A 2 1 0 to 2 0 LSB max 16 bits typ 15 bits min 3 LSB typ 6 LSB max including quantization ni com Appendix A Specifications Settling time Accuracy Step Size 16 LSB 4 LSB 2 LSB
23. AI connections to reject common mode noise e Use individually shielded twisted pair wires to connect AI signals to the device With this type of wire the signals attached to the AI and AI inputs are twisted together and then covered with a shield You then connect this shield only at one point to the signal source ground This kind of connection is required for signals traveling National Instruments Corporation 2 21 NI PXI 7831R User Manual Chapter 2 Hardware Overview of the NI PXI 7831R NI PXI 7831R User Manual 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 video monitor Separate the monitor from the analog signals as much as possible The following recommendations apply for all signal connections to the NI PXI 7831R Separate NI PXI 7831R signal lines from high current or high voltage lines These lines can induce currents in or voltages on the NI PXI 7831R signal lines if they run in parallel paths at a close distance To reduce the magnetic coupling between lines separate them by a reasonable distance if they run in parallel or run the lines at right angles to each other Do not run signal lines through conduits that also contain power lines Protect signal lines from magnetic fields caused by electric motors welding equipment breakers or transforme
24. B 68LP CB 68LPR TBX 68 NSC68 262650 Non shielded cable connects from 68 pin VHDCI male connector to two 26 pin female headers plus one 50 pin female header The pinout of these headers allows for direct connection to 5B backplanes for analog signal conditioning and SSR backplanes for digital signal conditioning 26 pin headers can connect to the following 5B backplanes for analog signal conditioning e 5 08 8 channel 5 01 16 channel 50 pin header can connect to the following SSR backplanes for digital signal conditioning 8 channel backplane 16 channel backplane e 32 channel backplane NSC68 5050 Non shielded cable connects from 68 pin VHDCI male connector to two 50 pin female headers The pinout of these headers allows for direct connection to SSR backplanes for digital signal conditioning 50 pin headers can connect to the following SSR backplanes for digital signal conditioning 8 channel backplane 16 channel backplane e 32 channel backplane 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 nearest to you Custom Cabling NI offers a variety of cables that you can use to connect signals to the NI PXI 7831R If you need to develop a custom cable NI provides a generic un terminat
25. CompactPCI chassis At least one cable and terminal block for connecting signals to the NI PXI 7831R NI PXI 7831R User Manual Chapter 1 Introduction 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 LabVIEW Help which is available by selecting Help VI Function amp How To Help from LabVIEW Getting Started with the RT Module NI PXI 7831R User Manual To set up and use the NI PXI 7831R with the FPGA Module and the RT Module you need the following items NI PXI 7831R The following software packages LabVIEW version 7 0 or later NI Device Drivers CD FPGA Module version 7 0 or later required to develop custom FPGA VIs for the RIO device RT Module version 7 0 or later PXI CompactPCI chassis and real time PXI controller One of the following host computers depending upon your application running Windows 2000 XP PC Laptop computer PXI CompactPCI embedded controller At least one cable and terminal block for connecting signals to the NI PXI 7831R Category 5 Cat 5 crossover cable if the real time PXI system is not configured on a network You need a regular network cable if you are configured on a network 1 4 ni com Chapter 1 Introduction The fo
26. E SIGNIFICANT INJURY TO A HUMAN 2 IN ANY APPLICATION INCLUDING THE ABOVE RELIABILITY OF OPERATION OF THE SOFTWARE PRODUCTS CAN BE IMPAIRED BY ADVERSE FACTORS INCLUDING BUT NOT LIMITED TO FLUCTUATIONS IN ELECTRICAL POWER SUPPLY COMPUTER HARDWARE MALFUNCTIONS COMPUTER OPERATING SYSTEM SOFTWARE FITNESS FITNESS OF COMPILERS AND DEVELOPMENT SOFTWARE USED TO DEVELOP AN APPLICATION INSTALLATION ERRORS SOFTWARE AND HARDWARE COMPATIBILITY PROBLEMS MALFUNCTIONS OR FAILURES OF ELECTRONIC MONITORING OR CONTROL DEVICES TRANSIENT FAILURES OF ELECTRONIC SYSTEMS HARDWARE AND OR SOFTWARE UNANTICIPATED USES OR MISUSES OR ERRORS ON THE PART OF THE USER OR APPLICATIONS DESIGNER ADVERSE FACTORS SUCH AS THESE ARE HEREAFTER COLLECTIVELY TERMED SYSTEM FAILURES ANY APPLICATION WHERE A SYSTEM FAILURE WOULD CREATE A RISK OF HARM TO PROPERTY OR PERSONS INCLUDING THE RISK OF BODILY INJURY AND DEATH SHOULD NOT BE RELIANT SOLELY UPON ONE FORM OF ELECTRONIC SYSTEM DUE TO THE RISK OF SYSTEM FAILURE TO AVOID DAMAGE INJURY OR DEATH THE USER OR APPLICATION DESIGNER MUST TAKE REASONABLY PRUDENT STEPS TO PROTECT AGAINST SYSTEM FAILURES INCLUDING BUT NOT LIMITED TO BACK UP OR SHUT DOWN MECHANISMS BECAUSE EACH END USER SYSTEM IS CUSTOMIZED AND DIFFERS FROM NATIONAL INSTRUMENTS TESTING PLATFORMS AND BECAUSE A USER OR APPLICATION DESIGNER MAY USE NATIONAL INSTRUMENTS PRODUCTS IN COMBINATION WITH OTHER PRODUCTS IN A MANNER NOT EVALUATED OR CONTEMPLATED BY NATIONAL
27. F input mode with bias resistors Refer to the Differential Connections for Nonreferenced or Floating Signal Sources section for more information about these input modes If you have a grounded source you should not reference the signal to AIGND You can avoid this reference by using DIFF or NRSE input modes Types of Signal Sources When configuring the input channels and making signal connections you must first determine whether the signal sources are floating or ground referenced The following sections describe these two signal types National Instruments Corporation 2 5 NI PXI 7831R User Manual Chapter 2 Hardware Overview of the NI PXI 7831R 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 transformers thermocouples battery powered devices optical isolator outputs and isolation amplifiers An instrument or device that has an isolated output is a floating signal source You must tie the ground reference of a floating signal to the NI PXI 7831R AIGND through a bias resistor to establish a local or onboard reference for the signal Otherwise the measured input signal varies as the source floats out of the common mode input range Ground Referenced Signal Sources A ground referenced signal source is connected in some way to the building system ground and is there
28. INSTRUMENTS THE USER OR APPLICATION DESIGNER IS ULTIMATELY RESPONSIBLE FOR VERIFYING AND VALIDATING THE SUITABILITY OF NATIONAL INSTRUMENTS PRODUCTS WHENEVER NATIONAL INSTRUMENTS PRODUCTS ARE INCORPORATED IN A SYSTEM OR APPLICATION INCLUDING WITHOUT LIMITATION THE APPROPRIATE DESIGN PROCESS AND SAFETY LEVEL OF SUCH SYSTEM OR APPLICATION 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 All National Instruments NI products are FCC Class A products Depending on where it is operated this Class A product could be subject to restrictions in the FCC rules In Canada the Department of Communications DOC of Industry Canada regulates wireless interference in much the same way Digital electronics emit weak signals during normal operation that can affect radio television or other wireless products All Class A products display a simple warning statement of one paragraph in length regarding interference and undesired operation The FCC rules have restrictions regarding the locations where FCC Class A products can be operated Consult the FCC Web site at www fcc gov for more information FCC DOC W
29. PXI 7831R User Manual Chapter 2 Hardware Overview of the NI PXI 7831R 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 provide an external pull up resistor to 5 V This resistor pulls up the 3 3 V digital output from the NI PXI 7831R to 5 V CMOS logic levels For detailed DIO specifications refer to Appendix A Specifications J Cautions Exceeding the maximum input voltage ratings which are listed in Table B 2 NI PXI 7831R I O Signal Summary can damage the NI PXI 7831R and the computer NI is not liable for any damage resulting from such signal connections Do not short the DIO lines of the NI PXI 7831R directly to power or to ground Doing so can damage the NI PXI 7831R by causing excessive current to flow through the DIO lines Refer to Appendix A Specifications for more information NI is not liable for any damage resulting from such signal connections If required by your application you can connect multiple NI PXI 7831R digital output lines in parallel to provide higher current sourcing or sinking capability If you connect multiple digital output lines in parallel your application must drive all of these lines simultaneously to the same value If you connect digital lines together and drive them to different values excessive current may flow through the DIO lines and dam
30. R User Manual The NI PXI 7831R can send and receive triggers through the PXI trigger bus which provides eight trigger lines that link all PXI slots in a bus segment These trigger lines connect to the FPGA on the NI PXI 7831R and can be used just like any of the other NI PXI 7831R DIO lines The PXI trigger lines can be used to synchronize an NI PXI 7831R to any other device that supports PXI triggers The PXI trigger lines on the NI PXI 7831R are PXI TRIG O 7 In addition the NI PXI 7831R can use the PXI star trigger line to send or receive triggers from a device plugged into slot 2 of the PXI chassis The PXI star trigger line on the NI PXI 7831R is PXI STAR The PXI 7831R can configure each PXI trigger line either as an input or an output signal Since each PXI trigger line in the PXI trigger bus is connected in parallel to all the PXI slots in a bus segment only one PXI device can drive a particular PXI trigger line at a time For example if one NI PXI 7831R is configured to send out a trigger pulse on PXI TRIG O0 the remaining devices on that PXI bus segment must have PXI TRIG 0 configured as an input 2 18 ni com Chapter 2 Hardware Overview of the NI PXI 7831R A 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 not liable for any damage resulting from such signal driving Refer to th
31. RIO device is still compatible as long as those pins on the sub bus are disabled by default and are never enabled UN Caution Damage can result if the J2 lines are driven by the sub bus NI PXI 7831R User Manual 1 2 ni com Chapter 1 Introduction Table 1 1 Pins Used by the NI PXI 7831R NI PXI 7831R Signal PXI Pin Name PXI J2 Pin Number PXI Trigger lt 0 7 gt PXI Trigger lt 0 7 gt A16 A17 A18 B15 B18 C18 E16 E18 PXI Clock 10 MHz PXI Clock 10 MHz E17 PXI Star Trigger PXI Star Trigger D17 LBLSTAR lt 0O 12 gt LBL lt 0 12 gt Al A19 C1 C19 C20 DI D2 D15 D19 E1 E2 E19 E20 LBR lt 0 12 gt LBR 0 12 A2 A3 A20 A21 B2 B20 C3 C21 D3 D21 E3 E15 E21 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 and use the NI PXI 7831R with Windows 2000 XP you need the following items National Instruments Corporation NI PXI 7831R The following software packages LabVIEW version 7 0 or later NI Device Drivers CD FPGA Module version 7 0 or later required to develop custom FPGA VIs for the RIO device PXI CompactPCI chassis and a PXI CompactPCI embedded controller running Windows 2000 XP or any computer running Windows 2000 XP and an MXI 3 link to a PXI
32. Reconfigurable 1 0 NI PXI 7831R User Manual Reconfigurable 1 0 Devices for PXI CompactPCl Bus Computers Wy NATIONAL April 2003 Edition P INSTRUMENTS Part Number 370489A 01 Worldwide Technical Support and Product Information ni com National Instruments Corporate Headquarters 11500 North Mopac Expressway Austin Texas 78759 3504 USA 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 3262 3599 Canada Calgary 403 274 9391 Canada Montreal 514 288 5722 Canada Ottawa 613 233 5949 Canada Qu bec 514 694 8521 Canada Toronto 905 785 0085 Canada Vancouver 514 685 7530 China 86 21 6555 7838 Czech Republic 420 2 2423 5774 Denmark 45 45 76 26 00 Finland 385 0 9 725 725 11 France 33 0 1 48 14 24 24 Germany 49 0 89 741 31 30 Greece 30 2 10 42 96 427 Hong Kong 2645 3186 India 91 80 51190000 Israel 972 0 3 6393737 Italy 39 02 413091 Japan 81 3 5472 2970 Korea 82 02 3451 3400 Malaysia 603 9059 6711 Mexico 001 800 010 0793 Netherlands 31 0 348 433 466 New Zealand 64 09 914 0488 Norway 47 0 32 27 73 00 Poland 48 0 22 3390 150 Portugal 351 210 311 210 Russia 7 095 238 7139 Singapore 65 6 226 5886 Slovenia 386 3 425 4200 South Africa 27 0 11 805 8197 Spain 34 91 640 0085 Sweden 46 0 8 587 895 00 Switzerland 41 56 200 51 51 Taiwan 886 2 2528 7227 United Kingdom 44 0 1635 523545 For further support information see the Technical Supp
33. XI trigger bus on the PXI backplane The RTSI bus can route timing and trigger signals between as many as seven PXI devices in your system Refer to Appendix A Specifications for detailed specifications of the RIO device Using PXI with CompactPCl Using PXI compatible products with standard CompactPCI products is an important feature provided by PXI Hardware Specification Revision 2 1 and PXI Software Specification Revision 2 1 If you use a PXI compatible plug in card in a standard CompactPCI chassis you cannot use PXI specific functions but you can still use the basic plug in card functions For example the RTSI bus on the RIO device is available in a PXI chassis but not in a CompactPCI chassis The CompactPCI specification permits vendors to develop sub buses that coexist with the basic PCI interface on the CompactPCI bus Compatible operation is not guaranteed between CompactPCI devices with different sub buses nor between CompactPCI devices with sub buses and PXI The standard implementation for CompactPCI does not include these sub buses The RIO device works in any standard CompactPCI chassis adhering to PICMG CompactPCI 2 0 R3 0 PXI specific features are implemented on the J2 connector of the CompactPCI bus Table 1 1 lists the J2 pins used by the NI PXI 7831R The NI PXI 7831R is compatible with any CompactPCI chassis with a sub bus that does not drive these lines Even if the sub bus is capable of driving these lines the
34. ackplanes This cable has a 68 pin male VHDCI connector on one end that plugs into the NI PXI 7831R MIO connector The other end of this cable provides two 26 pin female headers plus one 50 pin female header One of the 26 pin headers contains all the NI PXI 7831R analog input signals This connector can be plugged directly into a 5B backplane for analog input signal conditioning The NI PXI 7831R AI channels lt 0 7 gt are mapped to the 5B backplane channels lt 0 7 gt in sequential order The AI channels should be configured to use the NRSE input mode when using 5B signal conditioning The other 26 pin header contains all the NI PXI 7831R analog output signals This connector can be plugged directly into a 5B backplane for AO signal conditioning The NI PXI 7831R AO channels lt 0 7 gt are mapped to the 5B backplane channels lt 0 7 gt in sequential order The 50 pin header contains the 16 DIO lines available on the NI PXI 7831R MIO connector This header can be plugged directly into an SSR backplane for digital signal conditioning DIO lines lt 0 15 gt are mapped to the 5B backplane slots lt 0 15 gt in sequential order The 5B connector pinouts are compatible with 8 channel 5B08 backplanes and 16 channel 5 01 backplanes but since the NI PXI 7831R only provides 8 AI channels you only have access to the first 8 channels in a 16 channel backplane The SSR connector pinout is compatible with 8 16 24 and 32 channel SSR backpl
35. age the NI PXI 7831R Refer to Appendix A Specifications for more information NI is not liable for any damage resulting from such signal connections NI PXI 7831R User Manual 2 16 ni com Chapter 2 Hardware Overview of the NI PXI 7831R Figure 2 10 shows signal connections for three typical DIO applications VVV LED WV v TTL or DGND 5V LVCMOS lt Compatible Devices lt 4 14 t DIO lt 4 7 gt 5V CMOS 4 e oq 4 gt gt TTL LVTTL CMOS or LVCMOS Signal oy DIO lt 0 3 gt o 5V NAA gt Switch S DGND Connector NI PXI 7831R 8 8 V CMOS TUse a pull up resistor when driving 5 V CMOS devices Figure 2 10 Example Digital 1 0 Connections Figure 2 10 shows DIO lt 0 3 gt configured for digital input and DIO lt 4 7 gt configured for digital output Digital input applications include receiving TTL LVTTL CMOS or LVCMOS signals and sensing external device states such as the state of the switch shown in the figure Digital output applications include sending TTL or LVCMOS signals and driving external devices such as the LED shown in the figure The NI PXI 7831R SH68 C68 S shielded cable contains 34 twisted pairs of conductors To maximize the digital I O available on the NI PXI 7831R some of the DIO lines are twisted with power or ground as they are run through the cable and some DIO lines are tw
36. aling LVTTL and LVCMOS levels UN Caution Do not enable the local bus lines an adjacent device if the device drives anything other than 0 3 3V LVTTL signal levels on the NI PXI 7831R Enabling the lines in this way can damage the NI PXI 7831R NI is not liable for any damage resulting from enabling such lines The left local bus lines from the left peripheral slot of a PXI backplane slot 2 are routed to the star trigger lines of up to 13 other peripheral slots in a two segment PXI system This configuration provides a dedicated delay matched trigger signal between the first peripheral slot and the National Instruments Corporation 2 19 NI PXI 7831R User Manual Chapter 2 Hardware Overview of the NI PXI 7831R 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 lt 3 15 gt using the PXI LBLSTAR lt 0 12 gt Each device receives its trigger signal on its own dedicated star trigger line UN Caution Do not configure the NI PXI 7831R and another device to drive the same physical star trigger line simultaneously Such signal driving can damage the NI PXI 7831R and the other device NI is not liable for any damage resulting from such signal driving Refer to the PXI Hardware Specification Revision 2 1 and PXI Software Specification Revision 2 1 at www pxisa org for more information about PXI trig
37. anes You can connect to an SSR backplane containing a number of channels that does not equal the 16 DIO lines available on the 50 pin header In this case you only have access to the channels that exist on both the SSR backplane and the NSC68 262650 cable 50 pin header Figure B 3 shows the connector pinouts when using the NSC68 262650 cable B 6 ni com Appendix B Connecting 1 0 Signals AOO 1 2 NC Al0 1 2 AIO 01011 25 26 NC AOGNDO 3 4 NC AIGNDO 3 4 Alt 01010 27 28 NC AO1 5 6 AOGND1 Ali 5 6 AIGND1 DIO9 29 30 NC AO2 7 8 NC Al2 7 8 2 DIO8 31 32 NC AOGND2 9 10 NC AIGND2 9 10 AI3 DIO7 33 34 NC 11 12 AOGND3 Al3 11 12 AOGND3 DIO6 35 36 4 13 14 NC Al4 13 14 Al4 205 37 38 AOGND4 15 16 NC AIGND4 15 16 Al5 DIO4 39 40 DGND AOS 17 18 5 Al5 17 18 AOGND5 DIO3 41 42 AO6 19 20 NC Al6 19 20 Al6 DIO2 43 44 AOGND6 21 22 NC AIGND6 21 22 7 DIO1 45 46 DGND 7 23 24 AOGND7 Al7 23 24 AOGND7 200 47 48 25 26 NC AISENSE 25 26 NC 5 49 50 DGND AO 0 7 Connector Al 0 7 Connector DIO 0 15 Connector Pin Assignment Pin Assignment Pin Assignment NC 1121 NC NC 3141 NC NC 5 6 NC NC 7 8 NC NC 9 10 NC NC 11 12 NC NC 13 14 NC NC 15 16 NC DIO15 17 18
38. arnings This equipment generates and uses radio frequency energy and if not installed and used in strict accordance with the instructions in this manual and the CE marking Declaration of Conformity may cause interference to radio and television reception Classification requirements are the same for the Federal Communications Commission FCC and the Canadian Department of Communications DOC Changes or modifications not expressly approved by NI could void the user s authority to operate the equipment under the FCC Rules Class A Federal Communications Commission This equipment has been tested and found to comply with the limits for a Class A digital device pursuant to part 15 of the FCC Rules These limits are designed to provide reasonable protection against harmful interference when the equipment is operated in a commercial environment This equipment generates uses and can radiate radio frequency energy and if not installed and used in accordance with the instruction manual may cause harmful interference to radio communications Operation of this equipment in a residential area is likely to cause harmful interference in which case the user is required to correct the interference at their own expense Canadian Department of Communications This Class A digital apparatus meets all requirements of the Canadian Interference Causing Equipment Regulations Cet appareil num rique de la classe A respecte toutes les exigences du R glement su
39. asured voltage Figure 2 8 shows how to connect a grounded signal source to a channel on the NI PXI 7831R configured for NRSE input mode Ground Referenced Signal Source Common Mode Noise and Ground Potential Lo Al a ot Al Instrumentation Vs Amplifier T Measured oj Voltage e 1 E von x8 Channels SMF I qp 9e a a E c ae EA a EAE AISENSE STV AIGND Connector NRSE Input Mode Selected Figure 2 8 Single Ended Input Connections for Ground Referenced Signals Common Mode Signal Rejection Considerations Figures 2 5 and 2 8 show connections for signal sources that are already referenced to some ground point with respect to the NI PXI 7831R In these cases the instrumentation amplifier can reject any voltage caused by ground potential differences between the signal source and the device In addition with differential input connections the instrumentation amplifier can reject common mode noise pickup in the leads connecting the signal sources to the device The instrumentation amplifier can reject National Instruments Corporation 2 13 NI PXI 7831R User Manual Chapter 2 Hardware Overview of the NI PXI 7831R Analog Output common mode signals as long as and V input signals are both within their specified input ranges Refer to Appendix A
40. calibrated data For this reason the switch should only be switched to the ON position while you are using software to reconfigure the NI PXI 7831R for the desired power up behavior Afterwards you should return switch 1 to the OFF position Power Connections Two pins on each I O connector supply 5 V from the computer power supply using a self resetting fuse The fuse resets automatically within a few seconds after the overcurrent condition is removed The 5 V pins are referenced to DGND and can be used to power external digital circuitry Power rating 4 65 to 5 25 VDC at 1 A 250 mA max per 5 V pin 1 A max total for all 5 V lines on the device UN Caution Do not connect the 5 V power pins directly to analog or digital ground or to any other voltage source on the NI PXI 7831R or any other device under any circumstance Doing so can damage the NI PXI 7831R and the computer NI is not liable for damage resulting from such a connection Field Wiring Considerations Environmental noise can seriously affect the accuracy of measurements made with the NI PXI 7831R if you do not take proper care when running signal wires between signal sources and the device The following recommendations mainly apply to AI signal routing to the device although they also apply to signal routing in general Minimize noise pickup and maximize measurement accuracy by taking the following precautions Use differential
41. ctor 2 DIO Digital VO 40 PXI CompactPCI Bus National Instruments Corporation Figure 2 1 NI PXI 7831R Block Diagram 2 1 NI PXI 7831R User Manual Chapter 2 Hardware Overview of the NI PXI 7831R 00095 00 0 0 3 37 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 software configurable and the input range is fixed at 10 V The converters return data in two s complement format Table 2 1 shows the ideal output code returned for a given AI voltage Table 2 1 Ideal Output Code and AI Voltage Mapping Output Code Hex Input Description AI Voltage Two s Complement Full scale range 1 LSB 9 999695 7 Full scale range 2 LSB 9 999390 7FFB NI PXI 7831R User Manual 2 2 ni com Chapter 2 Hardware Overview of the NI PXI 7831R Table 2 1 Ideal Output Code and Al Voltage Mapping Continued Output Code Hex Input Description AI Voltage Two s Complement Midscale 0 000000 0000 Negative full scale range 1 LSB 9 999695 8001 Negative full scale range 10 000000 8000 Any input voltage
42. ctor pin assignments for the I O connectors on the NI PXI 7831R The DIO connector pin assignment applies to connectors lt 1 2 gt on the NI PXI 7831R The MIO connector pin assignment applies to connector 0 on the NI PXI 7831R NI PXI 7831R User Manual B 2 ni com Appendix B Connecting 1 0 Signals 34 68 Alo 34168 Alo 33 67 Dio37 AIGND1 33 67 AIGNDO 32 66 pioss Alt 32 66 pios 31 65 Al2 31 65 Al2 pioso 30 64 01031 AIGND3 30 64 AIGND2 0 28 29 63 DIO29 29 63 45V 28 62 0027 AM 28 62 45V 27 61 0026 AIGNDS 27 61 AIGND4 DGND 26 60 0025 Als 26 60 DGND 25 59 DIO24 Al 25 59 DGND 24 58 023 AIGND7 24 58 AIGND6 DGND 3 57 022 Aiz 23 57 Am 22 56 DIO21 No Connect 22 56 AISENSE DGND 21 55 DIO20 AOGNDO 21 55 Aoo DGND 20 54 0019 AOGND1 20 54 AO DGND 19 53 1 AOGND2 19 53 2 DGND 18 52 DIO17 AOGNDs 18 52 17 51 9016 4 17 51 AO4 DGND 16 50 215 AOGNDS 16 50 aos DGND 15 49 014 AOGND6 15 49 AO6 DGND 14 48 AOGND7 14 48 DGND 13 47 DiO12 DIO14 13 47 DIO15 DGND 12 46 DIO1 DIO12 12 46 DIO13
43. d measurements in RSE configuration and the bias current return point for differential measurements All three ground references AIGND AOGND and DGND are connected together on the NI PXI 7831R AISENSE AIGND Input Analog Input Sense This pin serves as the reference node for channels AI lt 0 7 gt when the device is configured for NRSE mode AO lt 0 7 gt AOGND Output Analog Output Channels 0 through 7 Each channel can source or sink up to 5 mA AOGND Analog Output Ground The analog output voltages are referenced to this node All three ground references AIGND AOGND and DGND are connected together on the NI PXI 7831R DGND Digital Ground These pins supply the reference for the digital signals at the I O connector as well as the 5 V supply All three ground references AIGND AOGND and DGND are connected together on the NI PXI 7831R DIO lt 0 15 gt DGND Input or Digital I O signals Connector 0 Output DIO lt 0 39 gt Connector lt 1 2 gt AN 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 Table B 2 NI is not liable for any damage resulting from such signal connections NI PXI 7831R User Manual B 4 ni com Appendix B Connecting 1 0 Signals Table B 2 NI PXI 7831R 1 0 Signal Summary
44. e CalDACs are automatically loaded with the newly calculated calibration constants the next time the NI PXI 7831R is powered on External Calibration NI PXI 7831R User Manual The NI PXI 7831R has an onboard calibration reference to ensure the accuracy of self calibration Its specifications are listed in Appendix A Specifications The reference voltage is measured at the factory and stored in the flash memory for subsequent internal calibrations This voltage is stable enough for most applications but if you are using your device at an extreme temperature or if the onboard reference has not been measured for a year or more you may want to externally calibrate your device An external calibration refers to calibrating your device with a known external reference rather than relying on the onboard reference During the external calibration process the onboard reference value is re calculated This compensates for any time or temperature drift related errors in the onboard reference which may have resulted since the last calibration You can save the results of the external calibration process to flash memory so that the new calibration constants are automatically loaded the next time the NI PXI 7831R is powered on and so that the newly measured onboard reference level is used for subsequent internal calibrations To externally calibrate your device be sure to use a very accurate external reference The reference should be several times mo
45. e PXI Hardware Specification Revision 2 1 and PXI Software Specification Revision 2 1 at www pxisa org for more information about PXI triggers PXI Local Bus The NI PXI 7831R can communicate with other PXI devices using the PXI local bus The PXI local bus is a daisy chained bus that connects each PXI peripheral slot with its adjacent peripheral slot on either side For example the right local bus lines from a given PXI peripheral slot connect to the left local bus lines of the adjacent slot Each local bus is 13 lines wide All of these lines connect to the FPGA on the NI PXI 7831R and can be used like any of the other NI PXI 7831R DIO lines The PXI local bus right lines on the NI PXI 7831R are PXI LBR lt 0 12 gt The PXI local bus left lines on the NI PXI 7831R are PXI LBLSTAR lt 0 12 gt The NI PXI 7831R can configure each PXI local bus line either as an input or an output signal Only one device can drive the same physical local bus line at a given time For example if an NI PXI 7831R is configured to drive a signal on PXI LBR lt 0 gt the device in the slot immediately to the right must have its PXI LBLSTAR lt 0 gt line configured as an input UN Caution Do not drive the same PXI local bus line with the NI PXI 7831R and another device simultaneously Such signal driving can damage both devices NI is not liable for any damage resulting from such signal driving The NI PXI 7831R local bus lines are only compatible with 3 3 V sign
46. e input signal requires a separate ground reference point or return signal e signal leads travel through noisy environments Differential signal connections reduce noise pickup and increase common mode noise rejection Differential signal connections also allow input signals to float within the common mode limits of the instrumentation amplifier Differential Connections for Ground Referenced Signal Sources Figure 2 5 shows how to connect a ground referenced signal source to a channel on the NI PXI 7831R configured in DIFF input mode 2 8 ni com Chapter 2 Hardware Overview of the NI PXI 7831R Ground Referenced Signal Source Common Mode Noise and Ground Potential ge en a ale a a a ea ee es aa a i UE Pet Al i Al nstrumentation Amplifier d Measured oH Voltage m X WENN d 8 Channels 1 i o AGND _ Connector DIFF Input Mode Selected 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 ground potential difference between the signal source and the NI PXI 7831R ground shown as V in Figure 2 5 In addition the instrumentation amplifier can reject common mode noise pickup in the leads connecting the signal sources
47. ed shielded cable that makes this task easier The NI PXI 7831R User Manual 1 10 ni com Unpacking Chapter 1 Introduction SHC68 NT S NI part 18904 1 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 corresponds to which NI PXI 7831R pin Using this cable you can quickly connect the NI PXI 7831R signals that you need to the connector of your choice without having to connect these signals to the VHDCI connector end of the cable Refer to Appendix B Connecting I O Signals for the NI PXI 7831R connector pinouts The RIO device is shipped in an antistatic package to prevent electrostatic damage ESD to the device ESD can damage several components on the device UN Caution Never touch the exposed pins of connectors To avoid such damage in handling the device take the following precautions e Ground yourself using a grounding strap or by holding a grounded object Touch the antistatic package to a metal part of the computer chassis before removing the device from the package Remove the device from the package and inspect the device for loose components or any sign of damage Notify NI if the device appears damaged in any way Do not install a damaged device into the computer Store the RIO device in the antistatic envelope when not in use Safety Information The following section co
48. emory Reconfigurable 1 0 Applications To create or obtain new VIs for your application you can use the FPGA Module which allows the application to be specified using a subset of LabVIEW Arbitrary functionality can be defined for the RIO device If you are using the FPGA Module refer to the FPGA Module examples located in LabVIEW 7 0 examples FPGA Software Development NI PXI 7831R User Manual You can use LabVIEW with the FPGA Module to program the NI PXI 7831R To develop real time applications that control the NI PXI 7831R you can use the RT Module with LabVIEW and the FPGA Module 1 8 ni com FPGA Module Chapter 1 Introduction 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 run on the FPGA on the RIO device These functions can control the I O timing and logic of the RIO device and can generate interrupts for synchronization The FPGA Module synthesizes a VI into a form that can be downloaded to the FPGA on the RIO device The Interactive Front Panel Communication with the FPGA Module allows you to interact with the VI running on the FPGA The FPGA Module also includes a palette of functions for use in LabVIEW for Windows or when targeting an RT Module device that create applications that wait for interrupts and that control the FPGA by programmatically reading and
49. f logic slices 5 120 Equivalent number of logic cells 11 520 Available embedded RAM 16 384 KB Timebase National Instruments Corporation A 5 NI PXI 7831R User Manual Appendix A Specifications Timebase accuracy With onboard base 1 100 ppm Phase locked to PXI 10 MHz clock 350 ps jitter 300 ps skew max Calibration Recommended warm up time 15 minutes Calibration interval year Onboard calibration reference DC level eee oid 5 000 V x3 5 mV actual value stored in flash memory Temperature coefficient 5 ppm C max Long term stability 20 ppm 41 000 h B Note To generate a calibration certificate for the NI PXI 7831R click On line Calibration Certificates at ni com calibration Bus Interface lod m Master slave Power Requirement 5 VDC 45 NI PXI 7831R 450 mA typ 700 mA max does not include current drawn from the 5 V line on the connectors 3 3 VDC 5 NI PXI 7831R s 335 mA typ 730 mA max Power available at I O connectors 4 65 to 5 25 VDC at 1 A total 250 mA per I O connector pin NI PXI 7831R User Manual A 6 ni com Appendix A Specifications Physical Dimensions not including connectors 16 0
50. fore already connected to a common ground point with respect to the NI PXI 7831R assuming that the 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 The difference in ground potential between two instruments connected to the same building power system is typically between 1 and 100 mV but can be much higher if power distribution circuits are improperly connected If a grounded signal source is improperly measured this difference may appear as a measurement error The connection instructions for grounded signal sources are designed to eliminate this ground potential difference from the measured signal Input Modes You can configure the NI PXI 7831R for one of three input modes DIFF RSE or NRSE The following sections discuss the use of single ended and differential measurements and considerations for measuring both floating and ground referenced signal sources Figure 2 4 summarizes the recommended input mode for both types of signal sources NI PXI 7831R User Manual 2 6 ni com Chapter 2 Hardware Overview of the NI PXI 7831R Input Signal Source Type 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
51. g signal source to a channel on the NI PXI 7831R configured for RSE input mode Al Floating T Signal Source S Measured Voltage i 16 x8Channels AISENSE AIGND O4 Instrumentation Amplifier 1 Connector RSE Input Mode Selected NI PXI 7831R User Manual Figure 2 7 Single Ended Input Connections for Nonreferenced or Floating Signals Single Ended Connections for Grounded Signal Sources NRSE Input Mode To measure a grounded signal source with a single ended input mode you must configure the NI PXI 7831R in the NRSE input mode The signal is then connected to the positive input of the NI PXI 7831R instrumentation 2 12 ni com Chapter 2 Hardware Overview of the NI PXI 7831R 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 AISENSE Any potential difference between the NI PXI 7831R ground and the signal ground appears as a common mode signal at both the positive and negative inputs of the instrumentation amplifier and this difference is rejected by the amplifier If the input circuitry of a NI PXI 7831R were referenced to ground in this situation as in RSE input mode this difference in ground potentials would appear as an error in the me
52. gers Switch Settings NI PXI 7831R User Manual Refer to Figure 2 2 for the location of switch SW1 For normal operation switch 1 is in the OFF position To prevent a VI stored in flash memory from loading to the FPGA upon power up you can move switch 1 to the ON position as shown in Figure 2 11 ON ON RA 123 123 a Normal Operation Default b Prevent VI From Loading Figure 2 11 Switch Settings on Switch SW1 To move switch 1 to the ON position complete the following steps 1 Power off and unplug the PXI CompactPCI chassis 2 Remove the NI PXI 7831R 3 Move switch 1 to the ON position as shown in Figure 2 11 4 Refer to the Installing the Hardware section of the Where to Start with the NI PXI 7831R document for installation instructions for reinserting the NI PXI 7831R into the PXI CompactPCI chassis 5 Plug in and power on the PXI CompactPCI chassis After completing this procedure a VI stored in flash memory does not load to the FPGA on power up You can use software to reconfigure the NI PXI 7831R if necessary To return to the default mode of loading from 2 20 ni com Chapter 2 Hardware Overview of the NI PXI 7831R flash memory repeat the procedure above but return switch 1 to the OFF position in step 3 iyi Note When the NI PXI 7831R is powered on with switch 1 in the ON position the analog circuitry does not return properly
53. ges defects malfunctions or service failures caused by owner s failure to follow the National Instruments installation operation or maintenance instructions owner s modification of the product owner s abuse misuse or negligent acts and power failure or surges fire flood accident actions of third parties or other events outside reasonable control Copyright Under the copyright laws this publication may not be reproduced or transmitted in any form electronic or mechanical including photocopying recording storing in an information retrieval system or translating in whole or in part without the prior written consent of National Instruments Corporation Trademarks LabVIEW MXI National Instruments ni com NI Developer Zone and RTSI are trademarks of National Instruments Corporation Product and company names mentioned herein are trademarks or trade names of their respective companies Patents For patents covering National Instruments products refer to the appropriate location Help Patents in your software the patents txt file on your CD or ni com patents WARNING REGARDING USE OF NATIONAL INSTRUMENTS PRODUCTS 1 NATIONAL INSTRUMENTS PRODUCTS ARE NOT DESIGNED WITH COMPONENTS AND TESTING FOR A LEVEL OF RELIABILITY SUITABLE FOR USE IN OR IN CONNECTION WITH SURGICAL IMPLANTS OR AS CRITICAL COMPONENTS IN ANY LIFE SUPPORT SYSTEMS WHOSE FAILURE TO PERFORM CAN REASONABLY BE EXPECTED TO CAUS
54. ion or only dry nonconductive pollution occurs The pollution has no influence e Pollution Degree 2 means that only nonconductive pollution occurs in most cases Occasionally however a temporary conductivity caused by condensation must be expected Pollution Degree 3 means that conductive pollution occurs or dry nonconductive pollution occurs that becomes conductive due to condensation You must insulate signal connections for the maximum voltage for which the NI PXI 7831R is rated Do not exceed the maximum ratings for the NI PXI 7831R Do not install wiring while the NI PXI 7831R is live with electrical signals Do not remove or add connector blocks when power is connected to the system Remove power from signal lines before connecting them to or disconnecting them from the NI PXI 7831R Operate the NI PXI 7831R at or below the installation category marked on the hardware label Measurement circuits are subjected to working voltages and transient stresses overvoltage from the circuit to which they are connected during measurement or test Installation categories establish Installation categories also referred to as measurement categories are defined in electrical safety standard IEC 61010 1 Working voltage is the highest rms value of an AC or DC voltage that can occur across any particular insulation NI PXI 7831R User Manual 1 12 ni com Chapter 1 Introduction standard impulse withstand voltage levels that common
55. is device with shielded cabling CE Compliance This product meets the essential requirements of applicable European Directives as amended for CE marking as follows Low Voltage Directive safety 73 23 EEC Electromagnetic Compatibility Directive ees 89 336 EEC Note Refer to the Declaration of Conformity DoC for this product for any additional regulatory compliance information To obtain the DoC for this product click Declaration of Conformity Information at ni com hardref nsf NI PXI 7831R User Manual A 8 ni com Connecting 1 0 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 eight AI lines eight AO lines and 16 DIO lines Figure B 1 shows the I O connector locations for the NI PXI 7831R The I O connectors are numbered starting at zero The text in parentheses indicates whether each I O connector is an MIO connector or a DIO connector National Instruments Corporation B 1 NI PXI 7831R User Manual Appendix B Connecting 1 0 Signals lt NATIONAL INSTRUMENTS NI PXI 7831R Reconfigurable Q 2 2 9 m 2 Q 2 2 z z m m g 3 o o 2 D 5 S 9 Figure B 1 NI PXI 7831R Connector Locations Figure B 2 shows the I O conne
56. isted with other DIO lines as they are run through the cable To obtain maximum signal integrity place National Instruments Corporation 2 17 NI PXI 7831R User Manual Chapter 2 Hardware Overview of the NI PXI 7831R 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 should be used for static signals or for non edge sensitive low frequency digital signals Examples of high frequency or edge sensitive signals include clock trigger pulse width modulation PWM encoder and counter signals Examples of static signals or non edge sensitive low frequency signals include LEDs switches and relays Table 2 4 summarizes these guidelines Table 2 4 DIO Signal Guidelines for the NI PXI 7831R Digital Lines SH68 C68 S Shielded Cable Signal Pairing Recommended Types of Digital Signals Connector 0 DIO lt 0 7 gt Connector 1 DIO lt 0 27 gt DIO line paired with power or ground All types high frequency or low frequency signals Connector 2 DIO lt 0 27 gt edge sensitive or non edge sensitive signals Connector 0 DIO lt 8 15 gt Connector 1 DIO lt 28 39 gt Connector 2 DIO lt 28 39 gt DIO line paired with another DIO line Static signals or non edge sensitive low frequency signals PXI Trigger Bus NI PXI 7831
57. ith the RT Module eee 1 4 Overview of Reconfigurable 1 5 Reconfigurable emere 1 5 Flexible Functionality eese rennen 1 5 User Defined Resources esee 1 6 Device Embedded Logic and Processing esses 1 6 Reconfigurable I O Architecture 1 6 Reconfigurable I O Applications eese een 1 8 Software Development peteret el erp id 1 8 FPGA UAI Uma HR etae 1 9 RT Module rto e rne a mood uio 1 9 Cables and Optional Equipment eese nennen rennen 1 9 Custom Cabling 5 59 enero 1 10 Unpacking te eB n iE OW tite 1 11 Safety Information ure ue Nat ege d i URN eta 1 11 Chapter 2 Hardware Overview of the NI PXI 7831R Analog Input eec esci t eR Pe El e CO dis 2 2 ttt eeite aia teque a ege ttp er tienen 2 3 Input Range eee ee ente etes denim 2 3 Connecting Analog Input Signals eese ener 2 4 Signal SOULCES 2 per emn m Gea ain ed Re 2 5 Floating Signal e 2 6 Ground Referenced Signal Sources see 2 6 Input Modes uem Ute need a hel eee I aes 2 6 Differential Connection Considerations DIFF Input Mode 2 8
58. lectrical supply installation lt 1 000V Examples include electricity meters and measurements on primary overcurrent protection devices and on ripple control units MAINS is defined as a hazardous live electrical supply system that powers equipment Suitably rated measuring circuits may be connected to the MAINS for measuring purposes National Instruments Corporation 1 13 NI PXI 7831R User Manual Hardware 0 verview 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 diagrams for the NI PXI 7831R Inpi ut Mux Calibration DACs M i Instrumentation 16 Bit Configuration lt Digital 16 Digital 40 1 1 1 1 1 1 1 1 i i n tee a LAH Amplifier 1 2 1 a E x8 Channels 2 pec Input y e e AISENSE o Voltage Temperature User 5 Reference Sensor Configurable i FPGA Calibration Se pea on RIO M Mx 2 Devices 1 Calibration A N DAC i x8 Channels Interface Bus PXI Local Bus RTSI Bus gt Connector 1 DIO Conne
59. limitations are first seen as distortion at higher signal frequencies G 7 NI PXI 7831R User Manual Glossary THD thermocouple TTL two s complement VDC VHDCI VI waveform NI PXI 7831R User Manual Total harmonic distortion the ratio of the total rms signal due to harmonic distortion to the overall rms signal in decibel or a percentage A temperature sensor created by joining two dissimilar metals The junction produces a small voltage as a function of the temperature Transistor transistor logic Given a number x expressed in base 2 with n digits to the left of the radix point the base 2 number 2n x Volts Volts direct current Very high density cabled interconnect Virtual instrument program in LabVIEW that models the appearance and function of a physical instrument Volts input high Volts input low Volts output high Volts output low Volts root mean square Multiple voltage readings taken at a specific sampling rate G 8 National Instruments Corporation
60. llowing 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 Module User Manual Where to Start with the NI PXI 7831R The LabVIEW Help which is available by selecting Help VI Function amp How To Help from LabVIEW Overview of Reconfigurable 1 0 This section introduces the concept of RIO and describes how to use the reconfigurable FPGA to build high level functions in hardware Refer to Chapter 2 Hardware Overview of the NI PXI 7831R for descriptions of the physical I O resources available on the NI PXI 7831R Reconfigurable 1 0 Concept The NI PXI 7831R device is based on a reconfigurable FPGA core surrounded by fixed I O resources The behavior of the reconfigurable core can be configured to better match the requirements of the measurement and control system The behavior can be fully user defined and implemented as a VI creating an application specific I O device In contrast a traditional data acquisition DAQ device uses a fixed core with predetermined functionality Flexible Functionality Flexible functionality allows the RIO device to match individual application requirements and to mimic the functionality of fixed I O devices including I O combinations not available in standard products For example you can configure a RIO device in one application for three 3
61. ly occur in electrical distribution systems The following is a description of installation categories e Installation Category I is for measurements performed on circuits not directly connected to the electrical distribution system referred to as MAINS voltage This category is for measurements of voltages from specially protected secondary circuits Such voltage measurements include signal levels special equipment limited energy parts of equipment circuits powered by regulated low voltage sources and electronics e Installation Category II is for measurements performed on circuits directly connected to the electrical distribution system This category refers to local level electrical distribution such as that provided by a standard wall outlet for example 115 V for U S or 230 V for Europe Examples of Installation Category II are measurements performed on household appliances portable tools and similar products e Installation Category is for measurements performed in the building installation at the distribution level This category refers to measurements on hard wired equipment such as equipment in fixed installations distribution boards and circuit breakers Other examples are wiring including cables bus bars junction boxes switches socket outlets in the fixed installation and stationary motors with permanent connections to fixed installations e Installation Category IV is for measurements performed at the primary e
62. names and hardware labels Italic text denotes variables emphasis a cross reference or an introduction to a key concept This font also denotes text that is a placeholder for a word or value that you must supply Text in this font denotes text or characters that you should enter from the keyboard sections of code programming examples and syntax examples This font is also used for the proper names of disk drives paths directories National Instruments Corporation vij NI PXI 7831R User Manual About This Manual programs subprograms subroutines device names functions operations variables filenames and extensions and code excerpts Reconfigurable 1 0 Documentation The NI PXI 7831R User Manual is one piece of the documentation set for your RIO system and application Depending on the hardware and software you use for your application you could have any of several types of documentation Use the documentation you have as follows Where to Start with the NI PXI 7831R This document lists what you need to get started describes how to unpack and install the hardware and contains information about connecting signals to the NI PXI 7831R NI PXI 7831R User Manual This manual contains detailed information about the NI PXI 7831R hardware LabVIEW FPGA Module Release Notes This document contains information about installing and getting started with the FPGA Module LabVIEW FPGA Module User Manual This manual de
63. nction I O MIO devices have a fixed functionality provided by an application specific integrated circuit ASIC You can change the functionality of the FPGA on the RIO device by using LabVIEW a graphical programming environment and the LabVIEW FPGA Module to create and download a custom virtual instrument VI to the FPGA You can reconfigure the RIO device with a new VI at any time Using LabVIEW you can graphically design the timing and functionality of the RIO device without having to learn the low level programming language or hardware description language HDL that is traditionally used for FPGA design If you only have LabVIEW and do not have the FPGA Module you cannot create new FPGA VIs but you can create VIs that run in LabVIEW to control existing FPGA VIs Some applications require tasks such as real time floating point processing or data logging while performing I O and logic on the RIO device You can use the LabVIEW Real Time RT Module to perform these additional applications while also communicating with and controlling the RIO device The RIO device contains flash memory to store VIs for instant loading of the FPGA when the system is powered on National Instruments Corporation 1 1 NI PXI 7831R User Manual Chapter 1 Introduction 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 P
64. ng Each of these functions consumes varying amounts of logic For example a typical 32 bit counter consumes 20 times more logic than a DIO resource while an 8 bit counter consumes five times more logic than a DIO resource Figures 1 2 and 1 3 illustrate the logic used by the FPGA in two different applications The application shown in Figure 1 2 requires many fixed I O resources leaving little logic left over for higher level functions The application in Figure 1 3 uses relatively few I O resources and has enough logic left over for several large functions EI DIO lt 0 7 gt Bus Interface DIO lt 8 15 gt Figure 1 2 FPGA Logic Use an Application with Many Fixed Resources National Instruments Corporation 1 7 NI PXI 7831R User Manual Chapter 1 Introduction m Rp pt SY BAN CENT 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 flash memory or from the software over the bus interface One advantage to using flash memory is that the VI can start executing almost immediately after power up instead of waiting for the computer to completely boot and load the FPGA Refer to the LabVIEW FPGA User Manual for more information about how to store your VI in flash m
65. ng of four or eight lines of digital input and or output Parts per million Pull up Pulse width modulation Stands for PCI eXtensions for Instrumentation PXI is an open specification that builds off the CompactPCI specification by adding instrumentation specific features G 6 National Instruments Corporation RAM resolution RIO rms RSE S s signal conditioning slew rate National Instruments Corporation Glossary 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 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 For example a system has 12 bit resolution one part in 4 096 resolution and 0 0244 of full scale Reconfigurable I O Root mean square Referenced single ended mode all measurements are made with respect to acommon reference measurement system or a ground Also called a grounded measurement system Seconds Samples Samples per second used to express the rate at which a DAQ board samples an analog signal The manipulation of signals to prepare them for digitizing The voltage rate of change as a function of time The maximum slew rate of an amplifier is often a key specification to its performance Slew rate
66. ntains important safety information that you must follow when installing and using the NI PXI 7831R Do not operate the NI PXI 7831R in a manner not specified in this document Misuse of the NI PXI 7831R can result in a hazard You can compromise the safety protection built into the NI PXI 7831R if the NI PXI 7831R is damaged in any way If the NI PXI 7831R is damaged return it to NI for repair National Instruments Corporation 1 11 NI PXI 7831R User Manual Chapter 1 Introduction 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 filler panels installed during operation of the NI PXI 7831R Do not operate the NI PXI 7831R in an explosive atmosphere or where there may be flammable gases or fumes If you must operate the NI PXI 7831R in such an environment it must be in a suitably rated enclosure If you need to clean the NI PXI 7831R use a soft nonmetallic brush Make sure that the NI PXI 7831R is completely dry and free from contaminants before returning it to service Operate the NI PXI 7831R only at or below Pollution Degree 2 Pollution is foreign matter in a solid liquid or gaseous state that can reduce dielectric strength or surface resistivity The following is a description of pollution degrees e Pollution Degree 1 means no pollut
67. of loading the source down with the series combination sum of the two resistors If for example the source impedance is 2 kQ and each of the two resistors is 100 kQ the resistors load down the source with 200 and produce a 1 gain error Both inputs of the instrumentation amplifier require a DC path to ground in order for the instrumentation amplifier to work If the source is AC coupled capacitively coupled the instrumentation amplifier needs a resistor between the positive input and AIGND If the source has low impedance choose a resistor that is large enough not to significantly load the source but small enough not to produce significant input offset voltage as a result of input bias current typically 100 kQ to 1 MQ In this case you can tie the negative input directly to AIGND If the source has high output impedance you should balance the signal path as previously described using the same value resistor on both the positive and negative inputs you should be aware that there is some gain error from loading down the source Single Ended Connection Considerations A single ended connection is one in which the NI PXI 7831R AI signal is referenced to a ground that can be shared with other input signals The input signal is tied to the positive input of the instrumentation amplifier and the ground is tied to the negative input of the instrumentation amplifier You can use single ended input connections for any input signal that
68. on in this document is accurate The document has been carefully reviewed for technical accuracy In the event that technical or typographical errors exist National Instruments reserves the right to make changes to subsequent editions of this document without prior notice to holders of this edition The reader should consult National Instruments if errors are suspected In no event shall National Instruments be liable for any damages arising out of or related to this document or the information contained in it EXCEPT AS SPECIFIED HEREIN NATIONAL INSTRUMENTS MAKES NO WARRANTIES EXPRESS OR IMPLIED AND SPECIFICALLY DISCLAIMS ANY WARRANTY OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE CUSTOMER S RIGHT TO RECOVER DAMAGES CAUSED BY FAULT OR NEGLIGENCE ON THE PART OF NATIONAL INSTRUMENTS SHALL BE LIMITED TO THE AMOUNT THERETOFORE PAID BY THE CUSTOMER NATIONAL INSTRUMENTS WILL NOT BE LIABLE FOR DAMAGES RESULTING FROM LOSS OF DATA PROFITS USE OF PRODUCTS OR INCIDENTAL OR CONSEQUENTIAL DAMAGES EVEN IF ADVISED OF THE POSSIBILITY THEREOF This limitation of the liability of National Instruments will apply regardless of the form of action whether in contract or tort including negligence Any action against National Instruments must be brought within one year after the cause of action accrues National Instruments shall not be liable for any delay in performance due to causes beyond its reasonable control The warranty provided herein does not cover dama
69. operating sequentially or in parallel It is possible to implement more complex algorithms such as control loops but the size of the FPGA limits the scope of these algorithms Reconfigurable 1 0 Architecture NI PXI 7831R User Manual Figure 1 1 which illustrates a generic representation of RIO device shows an FPGA connected to fixed I O resources and a bus interface Fixed I O Resource Fixed I O Resource lt lt Fixed I O Resource FPGA Fixed I O Resource Bus Interface Figure 1 1 High Level FPGA Functional Overview The fixed I O resources include A D converters ADCs D A converters DACs digital input or output lines or other I O resources Software accesses the RIO device through the bus interface and the FPGA provides 1 6 ni com Chapter 1 Introduction 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 consuming logic in the FPGA Each fixed I O resource used by the application consumes a small portion of the FPGA logic which is used to perform basic control of the fixed I O resource The bus interface also consumes a small portion of the FPGA logic to provide software access to the device The remaining FPGA logic is available for higher level functions such as timing triggering and counti
70. or pinouts when using the NSC68 5050 cable DIO23 DIO22 DIO21 DIO20 DIO19 DIO18 DIO17 DIO16 DIO15 DIO14 DIO13 DIO12 01011 01010 DIO9 DIO8 DIO7 DIOG DIO5 DIO4 DIO3 DIO2 DIO1 DIOO 5V NC NC NC NC NC NC NC NC NC DGND DGND DGND DGND DGND DGND DGND DGND DGND DGND DGND DGND DGND DGND DGND DGND DIO 0 23 Connector Pin Assignment NC NC NC NC NC NC NC NC DIO39 DIO38 DIO37 DIO36 DIO35 DIO34 DIO33 DIO32 DIO31 DIO30 DIO29 DIO28 DIO27 DIO26 DIO25 0024 5V OJAN Ol 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 37 35 36 38 39 40 41 42 43 44 45 46 47 49 50 DGND DGND DGND DGND DGND DGND DGND DGND DGND DGND DIO 24 39 Connector Pin Assignment Figure B 4 Connector Pinouts When Using the NSC68 5050 Cable B 8 ni com 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
71. ort and Professional Services appendix To comment on the documentation send email to techpubs ni com 2003 National Instruments Corporation All rights reserved 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 defective during the warranty period This warranty includes parts and labor The media on which you receive National Instruments software are warranted not to fail to execute programming instructions due to defects in materials and workmanship for a period of 90 days from date of shipment as evidenced by receipts or other documentation National Instruments will at its option repair or replace software media that do not execute programming instructions if National Instruments receives notice of such defects during the warranty period National Instruments does not warrant that the operation of the software shall be uninterrupted or error free A Return Material Authorization RMA number must be obtained from the factory and clearly marked on the outside of the package before any equipment will be accepted for warranty work National Instruments will pay the shipping costs of returning to the owner parts which are covered by warranty National Instruments believes that the informati
72. r le mat riel 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 The manufacturer includes a DoC for most hardware products except for those bought from OEMs In addition DoCs are usually not provided if compliance is not required for example electrically benign apparatus or cables To obtain the DoC for this product click Declaration of Conformity at ni com hardref nsf This Web site lists the DoCs by product family Select the appropriate product family followed by your product and a link to the DoC appears in Adobe Acrobat format Click the Acrobat icon to download or read the DoC The CE marking Declaration of Conformity contains important supplementary information and instructions for the user or installer Contents About This Manual COnDVentlons nie e e e ERU NE PIRE RR HER teed ee vii Reconfigurable I O Documentation sees viii Related Documentation oti teer tepore viii Chapter 1 Introduction About the Reconfigurable I O Devices seen 1 1 Using PXI with Compa ctPCL tte etie ebat ee Ee ted 1 2 What You Need 0 Get Started esee e ete idee he tee ciere 1 3 Getting Started with Windows 2000 XP 1 3 Getting Started w
73. re accurate than the device itself For a detailed calibration procedure for the NI PXI 7831R refer to the NI PXI 7831R Calibration Procedure by clicking Manual Calibration Procedures at ni com calibration 3 2 ni com 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 Inp t inodes senen n Type of ADC nette Resolution ettet Conversion Maximum sampling rate Input impedance Powered on Powered Overload ies Input signal range es Input bias current Input offset Input coupling Maximum working voltage signal common mode National Instruments Corporation A 1 DIFF RSE NRSE software selectable selection applies to all 8 channels Successive approximation 16 bits 1 in 65 536 4 us 200 kS s per channel 10 GQ in parallel with 100 pF 4 min 10 V 2 nA 1 nA DC Inputs should remain within 12 V of ground NI PXI 7831R User Manual Appendix
74. rs by running them through special metal conduits Refer to the NI Developer Zone tutorial Field Wiring and Noise Considerations for Analog Signals at ni com zone for more information 2 22 ni com 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 handled by the analog circuitry the data read from the AI channels or written to the AO channels in the FPGA VI is already calibrated Three levels of calibration are available for the NI PXI 7831R to ensure the accuracy of its analog circuitry The first level loading calibration constants is the fastest easiest and least accurate The intermediate level internal calibration is the preferred method of assuring accuracy in your application The last level external calibration is the slowest most difficult and most accurate Loading Calibration Constants The NI PXI 7831R is factory calibrated before shipment at approximately 25 C to the levels indicated in Appendix A Specifications The associated calibration constants the values that were written to the CalDACs to achieve calibration in the factory are stored in the onboard nonvolatile flash memory These constants are automatically read from the flash memory and loaded into the CalDACs by the NI PXI 7831R hardware on power up This occurs
75. sary NI PXI 7831R User Manual vi ni com About This Manual Conventions 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 O RIO device The NI PXI 7831R contains eight independent 16 bit analog input AT channels eight independent 16 bit analog output AO channels and 96 digital I O DIO lines lt gt Pg bold italic monospace 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 lt 3 0 gt 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 This icon denotes a note which alerts you to important information This icon denotes a caution which advises you of precautions to take to avoid injury data loss or a system crash When this symbol is marked on the device refer to the Safety Information section of Chapter 1 Introduction for precautions to take Bold text denotes items that you must select or click in the software such as menu items and dialog box options Bold text also denotes parameter
76. scribes how to use the FPGA Module LabVIEW Help tThis help contains information about using various virtual instruments VIs with the NI PXI 7831R and using the FPGA Module and the LabVIEW Real Time RT Module LabVIEW Real Time Module User Manual This manual contains information about how to install and use the RT Module Related Documentation The following documents contain information you might find helpful NI PXI 7831R User Manual NI Developer Zone tutorial Field Wiring and Noise Considerations for Analog Signals at ni com zone PICMG CompactPCI 2 0 R3 0 PXI Hardware Specification Revision 2 1 PXI Software Specification Revision 2 1 viii ni com 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 hardware and contains safety information about the NI PXI 7831R About the Reconfigurable 1 0 Devices Thank you for purchasing the NI PXI 7831R This RIO device has 96 digital I O DIO lines 8 independent 16 bit analog output AO channels and 8 independent 16 bit analog input AI channels A user reconfigurable field programmable gate array FPGA controls the digital and analog I O on the NI PXI 7831R The FPGA on the RIO device allows you to define the functionality and timing of the device whereas traditional multifu
77. ted directly to the ground tie point on the NI PXI 7831R You can use this signal for a general analog ground tie point to the NI PXI 7831R if necessary Connection of AI signals to the NI PXI 7831R depends on the input mode of the AI channels you are using and the type of input signal source With different input modes you can use the instrumentation amplifier in different ways Figure 2 3 shows a diagram of the NI PXI 7831R instrumentation amplifier NI PXI 7831R User Manual 2 4 ni com Chapter 2 Hardware Overview of the NI PXI 7831R Vin O Instrumentation Amplifier Measured Vn Voltage Vin Vine Vin 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 NI PXI 7831R Signals are routed to the positive and negative inputs of the instrumentation amplifier through input multiplexers on the device The instrumentation amplifier converts two input signals to a signal that is the difference between the two input signals The amplifier output voltage is referenced to the device ground The NI PXI 7831R ADC measures this output voltage when it performs A D conversions You must reference all signals to ground either at the source device or at the NI PXI 7831R If you have a floating source you should reference the signal to ground by using RSE input mode or the DIF
78. the analog output always increases as the values of the digital code input to it increase Multiplexer a switching device with multiple inputs that sequentially connects each of its inputs to its output typically at high speeds in order to measure several signals with a single analog input channel NI PXI 7831R User Manual Glossary noise NRSE OUT PCI port ppm pu PWM PXI NI PXI 7831R User Manual 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 and internal sources such as semiconductors resistors and capacitors Noise corrupts signals you are trying to send or receive Nonreferenced single ended mode all measurements are made with respect to common NRSE measurement system reference but the voltage at this reference can vary with respect to the measurement system ground Output pin a counter output pin where the counter can generate various TTL pulse waveforms 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 1 A communications connection on a computer or a remote controller 2 A digital port consisti
79. tput channel signal 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 something else DMA is the fastest method of transferring data to from computer memory Differential nonlinearity a measure in LSB of the worst case deviation of code widths from their ideal value of 1 LSB Digital output Electrically erasable programmable read only memory ROM that can be erased with an electrical signal and reprogrammed Field programmable gate array A configuration that is downloaded to the FPGA and that determines the functionality of the hardware An unwanted signal excursion of short duration that is usually unavoidable Hour Hardware in the loop Hertz G 4 National Instruments Corporation I O INL L LabVIEW LSB m max MIMO min MIO monotonicity mux National Instruments Corporation G 5 Glossary Input output the transfer of data to from a computer system involving communications channels operator interface devices and or data acquisition and control interfaces Relative accuracy Laboratory Virtual Instrument Engineering Workbench LabVIEW is a graphical programming language that uses icons instead of lines of text to create programs Least significant bit Meter Maximum Multiple input multiple output Minimum Multifunction I O A characteristic of a DAC in which
80. ve input of the instrumentation amplifier and connecting the negative side of the signal to AIGND and to the negative input of the instrumentation amplifier without any resistors at all This connection works well for DC coupled sources with low source impedance less than 100 However for larger source impedances this connection leaves the differential signal path significantly out of balance Noise that couples electrostatically onto the positive line does not couple onto the negative line because it is connected to ground Hence this noise appears as a differential mode signal instead of a common mode signal and the instrumentation amplifier does not reject it In this case instead of directly connecting the negative line to AIGND connect it to AIGND through a resistor that is about 100 times the equivalent source impedance The resistor puts the signal path nearly in balance so about the same amount of noise couples onto both connections which yields better rejection of electrostatically coupled noise Also this input mode does not load down 2 10 ni com Chapter 2 Hardware Overview of the NI PXI 7831R 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 positive input and AIGND as shown in Figure 2 6 This fully balanced input mode offers slightly better noise rejection but has the disadvantage
81. writing to the device 3 Note A software utility installed with the NI RIO Device Drivers CD allows users without the FPGA module to configure the NI PXI 7831R analog input mode synchronize to the PXI clock and configure the device to automatically load FPGA VIs when powered on RT Module The RT Module extends the LabVIEW development environment to deliver deterministic real time performance You can develop your RT Module application on a host computer with graphical programming and then download the program to run on an independent hardware target with a real time operating system The RT Module allows you to use the NI PXI 7831R in PXI systems being controlled in real time by a LabVIEW VI The NI PXI 7831R plug in device is designed as a single point AI AO and DIO complement to the RT Module Refer to ni com labviewrt for more information about the RT Module Cables and Optional Equipment NI offers a variety of products to use with your device including cables connector blocks and other accessories as follows National Instruments Corporation 1 9 NI PXI 7831R User Manual Chapter 1 Introduction Table 1 2 Cables and Accessories Cable Cable Description Accessories SH68 C68 S Shielded 68 pin VHDCI male Connects to the following standard connector to female 0 050 series D type connector The cable is constructed with 34 twisted wire pairs plus an overall shield 68 pin screw terminal blocks SCB 68 C

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