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Chapter 3 Connector and LED Information
I/O Connector Signal Descriptions
Table 3-1 describes the signals found on the I/O connectors. Not all signals are available on all 
devices.
Table 3-1.  I/O Connector Signals
Signal Name Reference Direction Description
AI GND — — Analog Input Ground—These terminals are the 
reference point for single-ended AI measurements in 
RSE mode and the bias current return point for DIFF 
measurements. All three ground 
references—AI GND, AO GND, and D GND—are 
connected on the device.
*
AI <0..207> Var ies Input Analog Input Channels 0 to 207
(MIO X Series Devices) For single-ended 
measurements, each signal is an analog input voltage 
channel. In RSE mode, AI GND is the reference for 
these signals. In NRSE mode, the reference for each 
AI <0..15> signal is AI SENSE; the reference for 
each AI <16..79> signal is AI SENSE 2; the 
reference for each AI <80..143> is AI SENSE 3; and 
the reference for each AI <144..207> is 
AI SENSE 4. 
For differential measurements on MIO X Series 
devices, AI 0 and AI 8 are the positive and negative 
inputs of differential analog input channel 0. 
Similarly, the following signal pairs also form 
differential input channels:
AI <1,9>, AI <2,10>, AI <3,11>, AI <4,12>, 
AI <5,13>, AI <6,14>, AI <7,15>, AI <16,24>, 
AI <17,25>, AI <18,26>, AI <19,27>, AI <20,28>, 
AI <21,29>, AI <22,30>, AI <23,31> and so on.
Also refer to the 
Connecting Ground-Referenced 
Signal Sources
 section of Chapter 4, Analog Input.
(Simultaneous MIO X Series Devices) For 
differential measurements on Simultaneous MIO 
X Series devices, AI 0+ and AI 0- are the positive 
and negative inputs of differential analog input 
channel 0. 
Also refer to the 
Connecting Analog Input Signals 
section of Chapter 4, 
Analog Input.