digital curve output does not correspond to the default - NI9375

[thhipp]

Hello all,

in the attached LabViewCode (LV2017) the given function is not implemented in the hardware.
Problem: output does not work regularly and all outputs are still on after the sequence is finished.

The idea for the function was to output a certain time pattern at the digital outputs with a sample rate of 1 kHz.
Because of a certain temporal accuracy (+/- 2ms) I decided consciously for the digital curve output.
The digital curve is from the time sequence as I had intended.

The execution of the VI runs flawlessly and the switching of the digital outputs is done, but not as I had intended in the timing of the curve.

The following two components are used as hardware:
cDAQ chassis: NI9171
module: NI9375 DI/DO

What is the reason for this?

Greetings Thomas

Greetings Thomas

[Kevin_Price · Accepted solution]

*One* thing you should do is to properly define the # of "samples per channel" at your call to DAQmx Timing.  And maybe that's all you need to do, but it's hard to say from the limited description you've given.

-Kevin P

[thhipp]

Hello Kevin,

thanks for your tip.

I don't understand, why the driver cannot recogonize automatically the numbers of samples, but with the attached design, it works now.

It looks for me more like a work around, but never mind. 🤔

Thomas

[Kevin_Price]

.The reason the driver doesn't "recognize" things automatically is that it supports several different ways of interacting with the data acq hardware.  Others would have different expections about what should happen automatically. 

To some extent, the unwired defaults are its version of making a few assumptions -- and as you've already seen, those won't always match your own.

-Kevin P