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 5V from the computer
power supply. For more information on the +5V terminals,
refer to the +5 V Power Source section in Chapter2,
Hardware Overview ofthe NI 78x xR.
Analog Signals (NI 783xR/784xR/785xR 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.
Allthree ground references—AIGND, AOGND, and
DGND—are connected to each other on the
NI783xR/784xR/785xR.
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 2.5mA.
AOGND — — Analog Output Ground—The analog output voltages
arereferenced to this node. All three ground
references—AIGND, AOGND, and DGND—are
connectedto each other on the NI 783xR/784xR/785xR.
Digital Signals (All NI 78xxR Devices)
DGND — — Digital Ground—These pins supply the reference for the
digital signals at the I/O connector and the 5V supply.
Allthree ground references—AIGND, AOGND, and
DGND—are connected to each other on the
NI783xR/784xR/785xR.
DIO<0..39>
Connector<0..3>
(NI781xR)
DIO<0..15>
Connector 0
(NI783xR/784xR/785xR)
DIO<0..39>
Connector <1..2>
(NI783xR/784xR/785xR)
DGND Input or
Output
Digital I/O signals.