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DAQ Assistant Analog Input

Good evening,

I have a little problem with the DAQ Assistant.

I have a system in which there are:

-DAQ Assistant for analog input

-PID that takes as process variable the analog input and a slide point as my setpoint

-DAQ Assistant for analog output.

When I run the VI, I have the slide point initialized from a value of 5 bar BUT the signal doesn't follow the slide point. It seems to go to zero and then suddenly to the correct value.

Why does the dynamic data want to go to zero at the beginning?

Thank you very much.

I have attached the VI

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You are doing both Analog Input and Analog Output, with the Output depending on the Input.  The AO module will start outputting a voltage when the code starts, whether or not it has received any "update", so you should expect to get an initial (default) voltage that only updates after the AI and other computation has a chance to run.

 

Bob Schor

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