PID - what is it anyway?

Always thought this was Pelvic Inflamitory Disease. If I had only known some adjustments could stop the pain.

I am just glad to have a resource such as this. I have spent 10 hours a day the last two months and can now program 5000 pretty well.
I went from having no knowledge of UDT's and AOI's to programming a number of working programs using them both this month, and tackled the Alma, which went much quicker as it was so familiar given years around tank sites.
However, I've dealt with PID's less often and saw there is a version in my RsLogix 5000, (hence the interest), as well as the PIDE, so THERE is the remainder of my November syllabus.
Alternating from here to the AB website to general googling has been helpful.
Thanks again for all the feedback, positive and negative. Any PID and PIDE resources are appreciated.
Most sincerely.
Jef

My PID training consisted of an engineer telling me: "This is "P" (a straight line), this is "D" (a curve), and don't mess with "D".

Still good advice!

No doubt. Good advice,
A moot point anyway, since my mini doesn't have Function Block and all my researching points that way for the PIDE autotune etc... latest and greatest Studio 5000. So when I open my free 30 days of emulate 5000 next month, which will have the function block, I'll dig a little then.
Happy Thanksgiving to all.
In all brief seriousness, it seems fundamental;
Proportional: a little off the SP, a little response and a lot off the SP, a lot of response, with basic physics ie... negating or opposing forces, (heat radiating from an oven, water in a discharge line being used thereby continuously dropping the pressure the pump is trying to raise thereby giving us a PV settling below the SP.)
Integral being the reaction to a cumulative error adding up over time to reach nearer the setpoint with derivative keeping an eye on rates of change ascent, descent, avoiding overshoot and other graphical tendencies .. Being an old MGD water flow meter calibrator using venturis, orifice plates and pressure differential, I did have to develop a must learn this stuff mentality, but I've worn it out now so to quote Kramer.
"I'm through with it starting... Now." : )
Tx again, back to programming

This is not good advice

rootboy said:

My PID training consisted of an engineer telling me: "This is "P" (a straight line), this is "D" (a curve), and don't mess with "D".

Still good advice!

Click to expand...

It is just spreading ignorance.

So when I open my free 30 days of emulate 5000 next month, which will have the function block, I'll dig a little then.

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well, you can probably "check out" the PIDE instruction – but I'm pretty sure that none of the "Emulator" software will actually run/execute any of the PID or the PIDE instructions ... I've never tried it myself – since I've always been blessed to have the "real live" software and hardware to work with ... (please correct me if you find out that I'm wrong) ...

anyway ...

I'm not sure (based on what you've posted so far) but if you haven't already seen the PID-related articles on my website, you might want to take a look at them when you get a chance ... you can freely download them as PDFs from the "Sample Lessons & Videos" page – no registration required ...

Peter Nachtwey said:

It is just spreading ignorance.

Click to expand...

Well, he found an apt student.