Studio 5000 Cascaded PIDE Loops

[mtrophy]

Good morning,

I am currently having a struggle of getting cascaded pide loops to work within studio 5000.

I have read and followed all the literature regarding it, added the "assume data available" pins, however when I have the two loops tied together I dont get any values generated via the CVEU on either function block.

Anyone with any experience regarding this willing to help would be greatly appreciated.

 

[Ken Moore]

On the Master loop:

Do you have the "action" direct vs reverse set up correctly. If the PV is < Set Point, should it open or close, if close, then Zero is correct.

 

[mtrophy]

Yes I have the action direction correctly set up. If I drop the InitPrimary pin, the primary loop begins controlling as expected. That removes the secondary loop from the cascade though.

Just spent a long time chatting with tech support and was unable to come to a resolution. I will provide an answer for what was found once I receive any information. As far as it was seen, all things are set correctly.. the blocks simply aren't feeding values as per example.

If anyone has any more suggestions I am very open to ideas.

 

[muusic_man]

The SP from FlueCascade PID is 0 and feeds the CVInitValue of BathTempControl PID. When initPrimary of FlueCascade PID is on it is intilaizing the CVEU of BathTempControl to 0. Start by removing that initialization being on all the time and just intialize BathTempControl PID in the PLC code with a proper CVUE when it's needed.

 

[celichi]

Did you get it to work?

Your Primary is not ramping up...

I think I see it, your Secondary is initializing your primary to 0!

 

[celichi]

Looks like your Secondary is not in Cascade Mode...