RSLogix 5000: PI vs PID vs PIDE

Can anyone give me a brief overview of what the key differences are between the PID ladder instruction and the PI & PIDE function block instructions?

I have a project coming up that will require me to use a Controllogix to do a speed control loop on a drive that runs in torque control mode and I was investigating options for the speed controller. I found the 1756-rm006 file on the Literature Library, but it only describes each instruction individually, and does not compare them to each other, at least not very obviously.

http://www.google.com/url?sa=t&rct=...t4CQDw&usg=AFQjCNEvME3zX5jPQNHSZ-LnUpU6aT4a4w

http://www.google.com/#hl=en&output...pw.r_qf.&fp=e2bb659d22ee5c38&biw=1587&bih=807

Thanks, Mickey. I found your links instructive.

Lancie1 said:

Thanks, Mickey. I found your links instructive.

Click to expand...

You're welcome.

And for the OP, I don't believe there is a separate PI instruction. PI would be the PID instruction without using the derivative term (gain).

The FB language supports a PI instruction. The PI instruction has some unique capabilities, including gain shaping. I used it only once for a pesky loop that proved difficult to control without gain shaping. Refer to the online help for more information on this instruction.

Greetings Paul351W ...

sorry that it took me several days to work this in between my other duties - but if you're still interested in the PID, PIDE, and PI comparisons that you asked for, I made an attempt to cover that for you in this new thread ...

http://www.plctalk.net/qanda/showthread.php?p=504603&postcount=1