Multiple channel PID controller

[Nidhi21]

This is the first time I am working on LabVIEW. I am trying to make a PID controller to control the acquired signals. I am working on LabVIEW 7.0 and for data Acquisition two data acquisition boards, MIC-3716 from Advatech are being used. A single board has 16 analog input channels and 2 analog output channels. When I created the Program for single channel it worked but now as I am trying to extend it for multiple channels, the output on all the four channels are same instead of being independent of each other, even when the set point of every channel is different. Right now I am only looping back the signals. AO0 is looped back to AI0-AI7 and AO1 is looped back to the rest 8 AI channels. I don't understand why it worked for single channel but not for multiple channels. A screenshot of the block diagram is attached. Please help me figure this out.

Thanks and regards

[GerdW]

Hi Nidhi,

you know the problem of attached images?

Answer: We cannot debug images in LabVIEW!

Please attach your VIs!

Until then:

- clean up the blockdiagram

- give labels to all controls/indicators!

- try to stay away from ExpressVIs and DDT wires - they only hide the real datatype of the wire…

- Which PID control do you use? It's not from PID toolkit…

- Is the PID VI reentrant?

[Nidhi21]

Sorry sir for the late reply. I had to get permission to post the file. Here is the file and the pid I am using.

[GerdW]

Hi Nidhi,

unfortunately your VIs are missing a lot of subVIs. Even your "PID..." mainly consists of two (also missing) subVIs…