User manual

Chapter 3 Software Overview

hold mode, and the second control call, which puts the module into track

mode, acquire data that was sampled at the time of the first control call.

One or more channels can be read while the module is in hold mode.

After you put the module back into track mode, you can repeat the

process to acquire new data.

Remember that the channel and gain parameters of the

function

calls refer to the DAQ device channels and gains. Simply use the data

acquisition channels that correspond to the module channels you want,

as described earlier in this section. Also be aware of the SSH Track/Hold

timing requirements described in the SCXI-1530/1531 section of the SCXI

Hardware chapter in the DAQ Hardware Overview Guide.

Figure 3-46 shows the function call sequence of a channel-scanning

application using an SSH module in parallel mode.

Figure 3-46. Channel-Scanning Operation Using an SSH Module in Parallel Mode

SCXI_Track_Hold_Setup

Acquire data from the desired channels using

interval scanning with the

SCAN and Lab_ISCAN

functions.

Ye s

Have you acquired all the data you need?

Configure the desired module for

interval scanning.

Disable the Track/Hold setup of the module to

free the counter resource on the data

acquisition board.

Scanned Data Acquisition

Done?

SCXI_Track_Hold_Setup