User manual

Chapter 3 Software Overview
NI-DAQ User Manual for PC Compatibles 3-122 ni.com
Figure 3-45. Single-Channel or Software-Scanning Operation Using an SSH Module
in Parallel Mode
The initial
SCXI_Track_Hold_Setup
call signals the driver that the
module is used in a single-channel application, and puts the module into
track mode. The first
SCXI_Track_Hold_Control
call latches, or
samples, all the module inputs; subsequent
AI
calls read the sampled
voltages. It is important to realize that all
AI
operations that occur between
the first
SCXI_Track_Hold_Control
call, which puts the module into
Single Analog Input
Ye s
No
Have you acquired all the data
you need from this module?
Acquire data from the desired channel on
the module using the
AI functions.
SCXI_Track_Hold_Control
SCXI_Track_Hold_Control
Maintain
Hold mode?
Done?
SCXI_Track_Hold_Setup
Do you wish to take more data while
the module is in Hold mode?
Ye s
No
Put the module back into Track mode
to sense the new input values.
Configure the desired module
for a single-channel operation.
Latch the analog inputs by
putting the module into Hold mode.
SCXI_Track_Hold_Setup
Disable the Track/Hold setup of the module to free
the counter resource on the data acquisition device.