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Appendix A

Connecting I/O Signals

R Series Intelligent DAQ User Manual

A-4

ni.com

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.

 

Table A-1.  

I/O Connector Signal Descriptions

Signal Name

Reference

Direction

Description

+5V

DGND

Output

+5 VDC Source—These pins supply 5 V from the computer 
power supply. For more information on the +5V terminals, 
refer to the 

+5 V Power Source

 section in Chapter 2, 

Hardware Overview of the NI 78xxR

.

Analog Signals (NI 783

x

R/784

x

R/785

x

R Only)

AI<0..7>+

AIGND

Input

Positive input for Analog Input channels 0 through 7.

AI<0..7>–

AIGND

Input

Negative input for Analog Input channels 0 through 7.

AIGND

Analog Input Ground—These pins are the reference point 
for single-ended measurements in RSE configuration and 
the bias current return point for differential measurements. 
All three ground references—AIGND, AOGND, and 
DGND—are connected to each other on the 
NI 783

x

R/784

x

R/785

x

R.

AISENSE

AIGND

Input

Analog Input Sense—This pin serves as the reference node 
for AI <0..7> when the device is configured for NRSE mode.

AO<0..7>

AOGND

Output

Analog Output channels 0 through 7. Each channel can 
source or sink up to 2.5 mA.

AOGND

Analog Output Ground—The analog output voltages 
are referenced to this node. All three ground 
references—AIGND, AOGND, and DGND—are 
connected to each other on the NI 783

x

R/784

x

R/785

x

R.

Digital Signals (All NI 78

xx

R Devices)

DGND

Digital Ground—These pins supply the reference for the 
digital signals at the I/O connector and the 5 V supply. 
All three ground references—AIGND, AOGND, and 
DGND—are connected to each other on the 
NI 783

x

R/784

x

R/785

x

R.

DIO<0..39>
Connector<0..3>
(NI 781

x

R)

DIO<0..15>
Connector 0
(NI 783

x

R/784

x

R/785

x

R)

DIO<0..39>
Connector <1..2>
(NI 783

x

R/784

x

R/785

x

R)

DGND

Input or 

Output

Digital I/O signals.

Summary of Contents for NI 781 R Series

Page 1: ...PXI 7842...

Page 2: ...Intelligent DAQ NI R Series Intelligent DAQ User Manual NI 781xR 783xR NI 784xR and NI 785xR Devices R Series Intelligent DAQ User Manual June 2008 370489F 01...

Page 3: ...ebanon 961 0 1 33 28 28 Malaysia 1800 887710 Mexico 01 800 010 0793 Netherlands 31 0 348 433 466 New Zealand 0800 553 322 Norway 47 0 66 90 76 60 Poland 48 22 3390150 Portugal 351 210 311 210 Russia 7...

Page 4: ...ctronic 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 Corporati...

Page 5: ...t 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 Thi...

Page 6: ...4 User Defined I O Resources 1 4 Device Embedded Logic and Processing 1 4 Reconfigurable I O Architecture 1 5 Reconfigurable I O Applications 1 6 Software Development 1 6 LabVIEW FPGA Module 1 6 LabVI...

Page 7: ...ded Signal Sources NRSE Input Mode 2 15 Common Mode Signal Rejection Considerations 2 16 Analog Output 2 16 Connecting Analog Output Signals 2 17 Digital I O 2 17 Connecting Digital I O Signals 2 17 R...

Page 8: ...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...

Page 9: ...re and software you use for your application you could have any of several types of documentation The documentation includes the following documents Getting Started with R Series Intelligent DAQ This...

Page 10: ...s to the LabVIEW Help and other Real Time Module documents for more information as you create the real time application To access this document refer to ni com manuals In LabVIEW 8 0 or later you can...

Page 11: ...er LabVIEW contains an extensive library of VIs and example programs for use with R Series devices To access the NI Example Finder open LabVIEW and select Help Find Examples then select Hardware Input...

Page 12: ...f the device You can change the functionality of the FPGA on the R Series device in LabVIEW using the LabVIEW FPGA Module to create and download a custom virtual Table 1 1 NI 78xxR R Series Intelligen...

Page 13: ...connected between devices R Series PXI devices access the RTSI bus through the PXI trigger lines implemented on the PXI backplane Refer to the NI R Series Intelligent DAQ Specifications available at n...

Page 14: ...functions in hardware Refer to Chapter 2 Hardware Overview of the NI 78xxR for descriptions of the I O resources on the NI 78xxR Reconfigurable I O Concept R Series Intelligent DAQ devices are based...

Page 15: ...endent timed loops with separate I O resources User Defined I O Resources You can create your own custom measurements using the fixed I O resources For example one application might require an event c...

Page 16: ...ents using the LabVIEW FPGA Module The FPGA logic provides timing triggering processing and custom I O measurements Each fixed I O resource used by the application uses a small portion of the FPGA log...

Page 17: ...s of FPGA VIs Software Development You can use LabVIEW with the LabVIEW FPGA Module to program the NI 78xxR To develop real time applications that control the NI 78xxR use LabVIEW with the LabVIEW Rea...

Page 18: ...onal Instruments NI RIO RIO Device Setup Help LabVIEW Real Time Module The LabVIEW Real Time Module extends the LabVIEW development environment to deliver deterministic real time performance You can w...

Page 19: ...to the NI SCB 68 terminal block to provide higher signal integrity and noise immunity SHC68 68 RDIO NI Recommended 1 2 NI SCB 68 High performance shielded cable wired specifically for signal connectio...

Page 20: ...maged in any way If the device is damaged return it to NI for repair Do not substitute parts or modify the device except as described in this document Use the device only with the chassis modules acce...

Page 21: ...a description of installation categories Measurement Category I is for measurements performed on circuits not directly connected to the electrical distribution system referred to as MAINS3 voltage Thi...

Page 22: ...t 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 mo...

Page 23: ...k diagram for the NI 7830R Figure 2 3 shows a block diagram for the NI 7831R 7833R 784xR 785xR Figure 2 1 NI 781xR Block Diagram Configuration Configuration Control Connector 0 DIO Connector 1 DIO Con...

Page 24: ...put Mode Mux AISENSE AIGND Calibration Mux Voltage Reference Temperature Sensor Calibration DACs 2 x4 Channels 16 Bit DAC Digital I O 16 User Configurable FPGA on RIO Devices Bus Interface Data Addres...

Page 25: ...AO channels 56 bidirectional DIO lines that you can configure individually for input or output and a Virtex II XC2V1000 FPGA AI AI PCI PXI CompactPCI Bus Input Mux Instrumentation Amplifier Input Mod...

Page 26: ...t independent 16 bit AI channels eight independent 16 bit AO channels and 96 bidirectional DIO lines that you can configure individually for input or output The NI PXI 7851R has a Virtex 5 LX30 FPGA t...

Page 27: ...uses two AI lines The positive input pin connects to the positive terminal of the onboard instrumentation amplifier The negative input pin connects to the negative input of the instrumentation amplifi...

Page 28: ...t 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 AISEN...

Page 29: ...ive and negative inputs of the instrumentation amplifier The instrumentation amplifier converts two input signals to a signal that is the difference between the two input signals The amplifier output...

Page 30: ...ut signal varies as the source floats out of the common mode input range Ground Referenced Signal Sources A ground referenced signal source is connected to the building system ground so it is already...

Page 31: ...resistors V1 AI i AIGND i V1 AI Vg AIGND Ground loop losses Vg are added to measured signal NOT RECOMMENDED V1 AI i AI i AIGND i V1 AI i AI i AIGND i See text for information on bias resistors Signal...

Page 32: ...rence signal or return connects to the negative input of the instrumentation amplifier Use differential input connections for any channel that meets any of the following conditions The input signal is...

Page 33: ...he ground potential difference between the signal source and the NI 783xR 784xR 785xR ground shown as Vcm in Figure 2 6 In addition the instrumentation amplifier can reject common mode noise pickup in...

Page 34: ...e side of the signal to the positive 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 r...

Page 35: ...strumentation 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 cho...

Page 36: ...785xR should not supply one In single ended input modes electrostatic and magnetic noise couples into the signal connections more than in differential input modes The coupling is the result of differ...

Page 37: ...tial difference between the NI 783xR 784xR 785xR ground and the signal ground appears as a common mode signal at both the positive and negative inputs of the instrumentation amplifier The instrumentat...

Page 38: ...com manuals for more information about input ranges Analog Output The bipolar output range of the NI 783xR 784xR 785xR AO channels is fixed at 10 V Some applications require that the AO channels powe...

Page 39: ...for either input or output When the system powers on the DIO lines are at high impedance To set another power on state you can configure the NI 78xxR to load a VI when the system powers on The VI can...

Page 40: ...ernal pull up resistor to 5 V This resistor pulls up the 3 3 V digital output from the NI 78xxR to 5 V CMOS logic levels Refer to the NI R Series Intelligent DAQ Specifications available at ni com man...

Page 41: ...f the switch shown in Figure 2 11 Digital output applications include sending TTL or LVCMOS signals and driving external devices such as the LED shown in Figure 2 11 The NI 78xxR SHC68 68 RDIO cable c...

Page 42: ...xamples 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...

Page 43: ...the RTSI bus is connected in parallel to all the other RTSI devices on the bus only one device should drive a particular RTSI trigger line at a time For example if one NI PXI 78xxR is configured to se...

Page 44: ...enable the local bus lines on an adjacent device if the device drives anything other than 0 3 3V LVTTL signal levels on the NI PXI 781xR 783xR Enabling the lines in this way can damage the NI PXI 781...

Page 45: ...of switches on the NI PXI 783xR For normal operation SW1 is in the OFF position To prevent a VI stored in flash memory from loading to the FPGA at power up move SW1 to the ON position as shown in Figu...

Page 46: ...Chapter 2 Hardware Overview of the NI 78xxR R Series Intelligent DAQ User Manual 2 24 ni com Figure 2 13 Switch Location on the NI PCI 781xR SW1 SW2 SW3...

Page 47: ...erview of the NI 78xxR National Instruments Corporation 2 25 R Series Intelligent DAQ User Manual Figure 2 14 Switch Location on the NI PXI 781xR NI PXI 7811R Reconfigurable I O CONNECTOR 2 DIO CONNEC...

Page 48: ...Chapter 2 Hardware Overview of the NI 78xxR R Series Intelligent DAQ User Manual 2 26 ni com Figure 2 15 Switch Location on the NI PCI 783xR SW1 SW2 SW3...

Page 49: ...PXI 783xR Figure 2 17 Switch Settings Complete the following steps to prevent a VI stored in flash memory from loading to the FPGA 1 Power off and unplug the PXI CompactPCI chassis or PCI computer 2...

Page 50: ...xR 783xR is powered on with SW1 in the ON position the analog circuitry does not return properly calibrated data Move the switch to the ON position only while you are using software to reconfigure the...

Page 51: ...ce Doing so can damage the device and the computer NI is not liable for damage resulting from such a connection The power rating on most devices is 4 75 to 5 25 VDC at 1 A Refer to the NI R Series Int...

Page 52: ...ual 2 30 ni com 3 Replace the broken fuse while referring to Figure 2 18 for the fuse locations Figure 2 18 NI 784xR 785xR Replacement Fuse Location 4 Reinstall the PCI or PXI device into the computer...

Page 53: ...for signals traveling through areas with large magnetic fields or high electromagnetic interference Route signals to the device carefully Keep cabling away from noise sources The most common noise sou...

Page 54: ...ost difficult and most accurate Loading Calibration Constants The NI 783xR 784xR 785xR is factory calibrated before shipment at approximately 25 C to the levels indicated in the device specifications...

Page 55: ...re a small amount of gain error and self calibration is sufficient The flash memory on the NI 783xR 784xR 785xR stores the results of an internal calibration so the CalDACs automatically load with the...

Page 56: ...elligent DAQ User Manual To externally calibrate your device use an external reference several times more accurate than the device itself For more information on externally calibrating your NI 783xR 7...

Page 57: ...to the NI 78xxR I O connectors Figure A 1 shows the I O connector pin assignments and locations for NI PCI 7811R 7813R and NI PXI 7811R 7813R Figure A 2 shows the I O connector pin assignments and loc...

Page 58: ...12 DIO13 DIO14 DIO15 DIO16 DIO17 DIO18 DIO19 DIO20 DIO21 DIO22 DIO23 DIO24 DIO25 DIO26 DIO27 DIO29 DIO30 DIO32 DIO34 DIO36 DIO38 35 1 36 2 37 3 38 4 39 5 40 6 41 7 42 8 43 9 44 10 45 11 46 12 47 13 48...

Page 59: ...0 55 21 56 22 57 23 58 24 59 25 60 26 61 27 62 28 63 29 64 30 65 31 66 32 67 33 68 34 1 No Connect on the NI 7830R DGND DGND DGND DGND DGND DGND DGND DGND DGND DGND DGND DGND DGND DGND DGND DGND DGND...

Page 60: ...the reference point for single ended measurements in RSE configuration and the bias current return point for differential measurements All three ground references AIGND AOGND and DGND are connected to...

Page 61: ...e Input Output Protection Volts On Off Source mA at V Sink mA at V Rise Time Bias 5V DO Analog Signals NI 783xR 784xR 785xR Only AI 0 7 AI 10 G in parallelwith 100 pF 42 35 2 nA AI 0 7 AI 10 G in para...

Page 62: ...e when using 5B signal conditioning The other 26 pin header contains all the NI 783xR 784xR 785xR analog output signals You can plug this connector directly into a 5B backplane for AO signal condition...

Page 63: ...AOGND4 AO5 AO6 AOGND6 AO7 No Connect No Connect No Connect AOGND1 No Connect No Connect AOGND3 No Connect No Connect AOGND5 No Connect No Connect AOGND7 No Connect 2 4 6 8 10 12 14 16 18 20 22 24 26...

Page 64: ...the NSC68 5050 Cable 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 42 44 46 48 50 1 3 5 7 9 11 13 15 17 19 21 23 25 27 29 31 33 35 37 39 41 43 45 47 49 DIO23 DIO22 DIO21 DIO20 DIO19 DIO18 DI...

Page 65: ...Figure B 1 for the general purpose switch configuration Figure B 1 General Purpose Switch Configuration for the SCB 68 Terminal Block After configuring the SCB 68 switches you can connect the I O sig...

Page 66: ...ndard Service Program Membership This program entitles members to direct access to NI Applications Engineers via phone and email for one to one technical support as well as exclusive access to on dema...

Page 67: ...product by visiting ni com certification Calibration Certificate If your product supports calibration you can obtain the calibration certificate for your product at ni com calibration If you searched...

Page 68: ...lossary Symbol Prefix Value p pico 10 12 n nano 10 9 micro 10 6 m milli 10 3 k kilo 103 M mega 106 G giga 109 Numbers Symbols Degrees Greater than Greater than or equal to Less than Less than or equal...

Page 69: ...nalog voltage to a digital number AI Analog input AI i Analog input channel signal AIGND Analog input ground signal AISENSE Analog input sense signal AO Analog output AO i Analog output channel signal...

Page 70: ...ode signal usually expressed in decibels dB common mode voltage Any voltage present at the instrumentation amplifier inputs with respect to amplifier ground CompactPCI Refers to the core specification...

Page 71: ...to from computer memory DNL Differential nonlinearity A measure in LSB of the worst case deviation of code widths from their ideal value of 1 LSB DO Digital output E EEPROM Electrically erasable prog...

Page 72: ...aphical programming language that uses icons instead of lines of text to create programs LSB Least significant bit M m Meter max Maximum MIMO Multiple input multiple output min Minimum MIO Multifuncti...

Page 73: ...vary with respect to the measurement system ground O OUT Output pin A counter output pin where the counter can generate various TTL pulse waveforms P PCI Peripheral Component Interconnect A high perfo...

Page 74: ...e I O rms Root mean square RSE Referenced single ended mode All measurements are made with respect to a common reference measurement system or a ground Also called a grounded measurement system RTSI R...

Page 75: ...unction of the temperature TTL Transistor transistor logic two s complement Given a number x expressed in base 2 with n digits to the left of the radix point the base 2 number 2n x V V Volts VDC Volts...

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