Simulate a control of a sine wave signal

[GerdW]

Hi Xebe,

unfortunately I'm stuck at LV2014 here, so could you please resave your VI for LV2014 and attach it again?

[XebeXUC]

I hope I did it correct.

Thanks for keeping up with me.

[GerdW]

Hi Xebe,

wow, you did it the "hard" way using the simulation toolkit. (I don't have this toolkit installed and so cannot run your VI.)

I was talking about the PID toolkit, available for free with recent LabVIEW versions (atleast better than Base version)!

[XebeXUC]

So you just mean the PID block? 

I'll try to use that one instead and keep you updated

Edit: Something more like this (attachment)

[GerdW]

Hi Xebe,

I simplified your VI even more!

Keep in mind: this simple VI does not include any "plant simulation", so the PID controller has no chance to ever reach its setpoint as the "control system" does not react on the PID output signal…

In the example finder you will find VIs demonstrating PID with some plant simulation included!

[XebeXUC]

Thanks a lot, this was very helpful.

Do you perhaps know if there's a way so that the PID only works when the PV goes outside the set limits?

[GerdW · Accepted solution]

Hi Xebe,

a way so that the PID only works when the PV goes outside the set limits?

With "real" PID controllers (available as hardware block) you most often have a deadband setting which exactly does what you request now.

You can fake this in LabVIEW quite easily:

IF ABS(pv-sp) <= deadband/2 THEN
  pv:=sp
ENDIF
output := PID(pv, sp)

 You find other threads on this topic in the forum…

[XebeXUC]

where exactly would i put in this code? 

And where do i fill in my high and low value between which it doesn't have to work? (I have little basic knowledge about code write programming)

Edit:

Found out a solution for the problem that seems to work.

Thanks a lot for your help and patience with me.