ControlLogix PIDE

Can anyone tell me the difference between program,operator and override modes with the PIDE instruction in RS Logix 5000, and when they are likely to be used?

AB has not been forthcoming with examples of how best to use this block--I have also been looking for some professional guidance in this matter.

Anyway, in the interim, I setup about 15 PIDE's on a CLogix chassis, replacing the same number of single-loop PID controllers. I ended up using my own configuration of their block--testing rigorously as I went for bugs. So far, so good.

To answer your question, pp 1-62 in AB's publication #1756-RM006D-EN-P states that the block can either be run by a software app. (presumably a computer program), or by Operator Interface. They are apparently giving us the ability to use a multi-layered control scheme, should we so choose to use it.

My scheme is run in Program mode with a "1" wired to the pin to keep the block in that mode at all times. I have had no issues using it this way--

Information on the PIDE function block and how it works. Includes information on using it in Cascade and Ratio Control applications. This is a two part document which covers the majority of functions incorporated in the PIDE block.
Catalog Number: 1756 Generic
DocFullNum: G9057916


answerbase id is 21894 for 2 zip files 5/14/2002 .. seems to be pretty forthcoming.

Another document that may be of help is PIDE white paper from RA

#LOGIX-WP008-EN-P

Thanks for the replies, in the time since posting I have browsed the white paper that william martin mentioned. The document is useful in that it explains what the functions do, but not when one would use them.

Trust me, I have all of the AB technotes and articles pertaining to this block, and they DO NOT go into any further detail beyond the two out-of-the-can examples you mentioned.

Further, there is no mention of what happens to the block when uploading/downloading, such as A/M mode, valve position and SP changes that occur.

The current info available is lacking and less seasoned programmers can ill afford trial-by-fire methods of integration.

I disagree with your conclusion.