I/O Connector Signal Descriptions - National Instruments NI 6221 User Manual

Chapter 3 Connector and LED Information

I/O Connector Signal Descriptions

Signal Name
AI GND
AI <0..79>
AI SENSE,
AI SENSE 2
M Series User Manual
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
Reference Direction
—
Varies Input
— Input
— 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.
Analog Input Channels 0 to 79—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..63> and AI <64..79> signal is AI SENSE 2.
For differential measurements, 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, AI 9>, <AI 2, AI 10>, <AI 3, AI 11>,
<AI 4, AI 12>, <AI 5, AI 13>, <AI 6, AI 14>,
<AI 7, AI 15>, <AI 16, AI 24>, <AI 17, AI 25>,
<AI 18, AI 26>, <AI 19, AI 27>, <AI 20, AI 28>,
<AI 21, AI 29>, <AI 22, AI 30>, <AI 23, AI 31>,
<AI 32, AI 40>, <AI 33, AI 41>, <AI 34, AI 42>,
<AI 35, AI 43>, <AI 36, AI 44>, <AI 37, AI 45>,
<AI 38, AI 46>, <AI 39, AI 47>, <AI 48, AI 56>,
<AI 49, AI 57>, <AI 50, AI 58>, <AI 51, AI 59>,
<AI 52, AI 60>, <AI 53, AI 61>, <AI 54, AI 62>,
<AI 55, AI 63>, <AI 64, AI 72>, <AI 65, AI 73>,
<AI 66, AI 74>, <AI 67, AI 75>, <AI 68, AI 76>,
<AI 69, AI 77>, <AI 70, AI 78>, <AI 71, AI 79>
Also refer to the
Sources section of Chapter 4,
Analog Input Sense—In NRSE mode, the reference for
each AI <0..15> signal is AI SENSE; the reference for
each AI <16..63> and AI <64..79> signal is
AI SENSE 2. Also refer to the
Ground-Referenced Signal Sources
Analog Input
3-2
Description
Connecting Ground-Referenced Signal
Analog Input.
Connecting
section of Chapter 4,
ni.com