DataAcqusitionToolbox write has a delay

I am using a NI DAQ. I have code that follows this skeleton code:

dq = daq(...)
dq.addinput(...)
dq.addoutput(...)

dq.start();
tic
dq.write(some_output)
toc

The issue is that in this timer, MATLAB consistently takes ~ 0.7s longer than expected. For example, if my daq is running at a rate of 1000Hz, and my output is 3000 samples, total time to run would be ~3.7s, rather than an expected 3s.

Digging into the profiler, this seems to be due to just the delay required to start up the hardware for the daq or something related, but I would like to minimize or eliminate this delay. Any ideas?

[Mario Malic]

"If the DataAcquisition has both input and output channels, the input acquisition begins and ends at the same time as the output generation, resulting in the same number of scans."

Maybe your output signal is longer?

[Kevin]

I've confirmed that my output signal should be the exact expected amount of time.

Answer 1

[Mario Malic]

Try preload