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Table b-1. i/o connector signal descriptions, Table b-2. ni 781xr i/o signal summary, Ni 781xr i/o – National Instruments NI 781xR User Manual

Page 36: Signal summary, Can damage, Connecting to compactrio extension i/o chassis

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Appendix B

Connecting I/O Signals

NI 781xR User Manual

B-4

ni.com

end of the cable into the appropriate I/O connector and connect the other
end of the cable to the appropriate signal accessory.

Caution

Connections that exceed any of the maximum ratings of input or output signals

on the NI 781xR can damage the NI 781xR and the computer. Maximum input ratings for
each signal are given in the Protection (Volts) On/Off column of Table B-2. NI is not liable
for any damage resulting from such signal connections.

Connecting to CompactRIO Extension I/O Chassis

You can use the CompactRIO R Series Expansion chassis and CompactRIO
I/O modules with the NI 781xR. Refer to the CompactRIO R Series
Expansion System Installation Instructions
for information about
connecting the chassis to the NI 781xR.

Table B-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 using a self-resetting 1 A fuse. No more than
250 mA should be pulled from a single pin.

DGND

Digital Ground—These pins supply the reference for the
digital signals at the I/O connector as well as the 5 V supply.

DIO<0..39>

DGND

Input or

Output

Digital I/O signals.

Table B-2. NI 781xR I/O Signal Summary

Signal Name

Signal

Type and
Direction

Impedance

Input/

Output

Protection

(Volts)

On/Off

Source

(mA at V)

Sink

(mA at V)

Rise

Time

Bias

+5V

DO

DGND

DO

DIO<0..39>
Connector<0..3>

DIO

–0.5 to +7.0

5.0 at 2.4

5.0 at 0.4

12 ns

DIO = Digital Input/Output

DO = Digital Output