Multiple scxi modules and chassis – National Instruments Measure Data Acquisition User Manual

Page 26

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Chapter 3 Using SCXI with Measure DAQ

© National Instruments Corporation

3-3

Measure Data Acquisition User Manual

z

’ in the SCXI channel string represents the actual channel number

(e.g.

3

). Channels on the SCXI modules are numbered starting at zero.

You specify a range of channels on your SCXI modules by listing the
first and last channel separated with a colon (e.g.

0:5

).

You only use the SCXI channel string when the SCXI is operating in
multiplexed mode and channels are multiplexed onto one or more
channels of the data acquisition device. In parallel mode, specify the
channel of your data acquisition device to acquire. Each channel on
your DAQ device is mapped in hardware to one channel on a SCXI
module in parallel mode.

Multiple SCXI Modules and Chassis

In the scan list of your DAQ AI task, you can specify channels from
multiple SCXI modules or chassis by adding multiple entries to the
scan list. Repeat the Add operation for each SCXI module. However,
you can specify only one group of consecutive channels per SCXI
module in the scan list. You must specify consecutive channels in an
incremental order (e.g.

ob0!sc1!md1!0:5,

ob0!sc1!md2!10:19

). In the Measure DAQ Task Dialog Box, the

channel setting would be listed as follows. The two lines in the scan list
on the right are added separately by twice filling in the channel field on
the left and clicking on the Add>> button, as shown in
Figure 3-1.

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