Multiple Analog Channels and Tasks in Daq Assistant

[anomynous]

Hello,

I am trying to use Daq assistant to take multiple inputs and multiple outputs. I am running a proportional control scheme using the voltage returned from a pressure gauge to output a voltage control to a pump.

I have no problem when trying to do this with only one input and one output (see "Pressure Height Control (MIKE)"). 

I realize the three input signals must come from one DAQ assistant and the three outputs must also come from one DAQ assistant. The trouble I am having is splitting the three signals to their respective proportional control loop, and then I am also struggling taking the result and outputting it into one single DAQ assistant output to control each pump based on its specific pressure input.

For the splitting of the signals I currently have them running to signal selectors, and I have chosen signal 0, 1, and 2 respectively. The problem I run into here is error 20023; "The following conditions must be met: 0 < f_low <= f_high <= fs/2." These signals don't work with the filter I have them running through afterwards.

As for merging the signals before the output Daq assistant, I do not know what the proper way is to merge the data. I need to make sure that the correct pressure gauge data gets linked to the proper pump.

I would appreciate any help, and can answer questions if anything is unclear.

[GerdW]

Hi anomynous,

I am trying to use Daq assistant to…

You really should try to get rid of all those ExpressVIs.

DAQmx is really easy!

I am also struggling taking the result and outputting it into one single DAQ assistant output to control each pump based on its specific pressure input.

When you still want to use DAQAssistent: open its configuration dialog, and think about that blue "+" icon in the channel configuration…

For the splitting of the signals I currently have them running to signal selectors, and I have chosen signal 0, 1, and 2 respectively.

I don't see that in your VIs. (But I guess you use even more ExpressVIs…)

The problem I run into here is error 20023; "The following conditions must be met: 0 < f_low <= f_high <= fs/2." These signals don't work with the filter I have them running through afterwards.

Apparently you reduced the number of samples you send to your filters…

(You still have to obey Mr. Shannon and Mr. Nyquist!)

I do not know what the proper way is to merge the data.

As you are a friend of excessive ExpressVI usage: MergeSignal…