PID Setpoint Profile

[desduen]

Hello guys

i am working on project using NI-USB 6251 and labview. i am using PID Setpoint Profile VI to make setpoint 7Volt at t=0 and 0Volt at t=5, then back to 7V at t=10 and 0V again at 15s, repeatedly (7V every 10s) until i stop running the VI. any ideas?

Thank you for your help

[mikeporter]

Yeah, I have lots of ideas but your question has far too few details to tell me which are the good ideas. You might want to try going through the LabVIEW tutorials and then see if you have any ideas of your own.

Mike...

[desduen]

hello mikeporter, thanks for your answer.

i am sorry if my question is not worth to ask. i am new at labview and daq device, and i will keep learning .

about my question, i mean i know how to make PID setpoint profile (using PID setpoint profile.VI) like   7Volt at t=0 and 0Volt at t=5, then back to 7V at t=10 and 0V again at 15s.... but i don't know how to make PID setpoint repeatedly 7V every 10s until i stop running the VI.

thank you very much for your help

[mikeporter]

One way to do it is to have a loop that just toggles back and forth between the two values and use a timer to control how fast it toggles. It's not a great solution but it would work. You will discover many better solutions if you go through the LabVIEW tutorials.

Mike...

[Barp · Accepted solution]

After you define the profile to be used, you just need to 'toggle' the 'reset' and the function will start the profile again, as t=0. This example shows how you can start by pressing a button:

 C:\Program Files (x86)\National Instruments\LabVIEW 2015\examples\control\PID\Setpoint Profile Simulator.vi

However, if you really want to restart automatically, wire the 'profile complete?' output through a shift register to the 'reinitialize?' input and the profile will be repeated continuously. This other example does exactly this:

 C:\Program Files (x86)\National Instruments\LabVIEW 2015\examples\control\PID\Setpoint Profile with Gain Scheduling on Rising and Falling.vi

By the way, if you look in this folder:

C:\Program Files (x86)\National Instruments\LabVIEW 2015\examples\control\PID

You will see several example that probably will be interesting for you to learn how to use LabVIEW and the Control functions.

Hope this helps,