Measurement Computing Data Acquisition Systems rev.10.4 - Manual (Page 211)

The driver will automatically calculate the number of complete output update cycles in the file using the offset
information, the number of channels currently configured for waveform/pattern output, the size of the data
samples and the total file size.
Update Cycle Data Blocks
The waveform/pattern output file is organized into sequences of update data blocks. Each update data block
represent the sample data necessary to update all output channels configured for waveform/pattern output for
one output cycle. Each output cycle is initiated by an update clock pulse (see daqDacWaveSetFreq and
daqDacWaveSetClockSource
). The sample data is ordered according to the output channel for which it
will be output. Each update data block is ordered as follows:
DAC0 DAC1 DAC2 DAC3 P3 DO
If any of the above channels is not configured for waveform/pattern output then it will simply not be included
in the update data block, however, the channel ordering will not change. If for example a waveform/pattern
output is configured for DAC0, DAC2 and P3 DO will have the following update data block:
DAC0 DAC2 P3 DO
Programmer’s Manual 908494 Daq API Command Reference 4.4-29