Three PID block in a RSLogix5000 tasks

[logix_fan]

Hi !

Here is my first post

I want to implement three (3) independent PID controlers (block) in a Controllogix controller. They will be used to control temepratures in a three different places.

I guess, each of the PID block must be place separate periodic tasks ? I am right ?
I do not want to use event triggering.

It will be my first PID implemented program.

Thank you.

 

[Peter Nachtwey]

You can place all three in the same task. The problem is that when that one tasks runs it will run all PIDs UNLESS, you make each PID run every third time. For instance you can run the task every second but run each PID every 3 seconds, each one staggered from the other by one second.