User's Manual

Chapter 4 Analog Input

pairs that form differential input channels, refer to the I/O Connector Signal

Descriptions section of Chapter 3, Connector Information.

Caution The maximum input voltages rating of AI signals with respect to AI GND (and

for differential signals with respect to each other) are listed in the specifications document

for your device. Exceeding the maximum input voltage of AI signals distorts the

measurement results. Exceeding the maximum input voltage rating also can damage the

device and the computer. NI is not liable for any damage resulting from such signal

connections.

AI ground-reference setting is sometimes referred to as AI terminal

configuration.

Configuring AI Ground-Reference Settings in Software

You can program channels on an M Series device to acquire with different

ground references.

To enable multimode scanning in LabVIEW, use

NI-DAQmx Create

Virtual Channel.vi

of the NI-DAQmx API. You must use a new VI for

each channel or group of channels configured in a different input mode. In

Figure 4-3, channel 0 is configured in differential mode, and channel 1 is

configured in RSE mode.

Figure 4-3. Enabling Multimode Scanning in LabVIEW

To configure the input mode of your voltage measurement using the DAQ

Assistant, use the Terminal Configuration drop-down list. Refer to the

DAQ Assistant Help for more information about the DAQ Assistant.

To configure the input mode of your voltage measurement using the

NI-DAQmx C API, set the terminalConfig property. Refer to the

NI-DAQmx C Reference Help for more information.