User`s guide

Operation Theory
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4.1.2 Software conversion with polling data transfer
acquisition mode (Software Polling)
This is the easiest way to acquire single A/D data. The A/D converter starts
one conversion whenever the dedicated software command is executed.
Then the software would poll the conversion status and read back the A/D
data when it is available.
This method is very suitable for applications that need to process A/D data
in real time. Under this mode, the timing of the A/D conversion is fully
controlled by software. However, it is difficult to control the A/D conversion
rate.
4.1.2.1 Specifying Channels, Gains, and input configurations in the
Channel Gain Queue
In the Software Polling and Programmable Scan Acquisition mode, the
channel, gain, polarity, and input configuration (RSE, NRSE, or DIFF) can
be specified in the
Channel Gain Queue
. You can fill the channel number
in the Channel Gain Queue in any order. The channel order of acquisition
will be the same as the order you set in the Channel Gain Queue. There-
fore, you can acquire data with user-defined channel orders and with dif-
ferent settings on each channel.
When the specified channels have been sampled from the first data to the
last data in the Channel Gain Queue, the settings in Channel Gain Queue
are maintained. Users don’t need to re-configure the Channel Gain Queue
to keep on sampling data in the same order. The maximum number of
entries you can set in the Channel Gain Queue is 512.
Example:
First set entries in Channel Gain Queue:
Ch3 with bipolar ±10V, RSE connection
Ch1 with bipolar ±2.5V, DIFF connection
Ch2 with unipolar 5V, NRSE connection
Ch1 with bipolar ±2.5V, DIFF connection
Read 10 data by software polling method
The acquisition sequence of channels is: 3, 1, 2, 1, 3, 1, 2, 1, 3, 1,…