Sign in to follow this  
Followers 0
ssommers

RSLogix 5000 printout PLEASE

6 posts in this topic

Can someone print this file to a pdf for me? I don't have RSL5000 yet, but need to debug an already installed machine. TIA! Susan edit: I removed the program since the printout's been done. Edited by ssommers

Share this post


Link to post
Share on other sites
[susan, please find the attached PDF file. :) MarkF13V08.pdf

Share this post


Link to post
Share on other sites
Thank you, thank you, thank you! Susan

Share this post


Link to post
Share on other sites
Greetings Susan ... I also printed your original file to a PDF the other day, but before I could post it, servant had already taken care of it for you ... I didn’t mean to pry (and I didn’t have time to look very deep) - but I did glance at the program and noticed that the PIDs are NOT being properly “triggered” ... that accounts for the extremely low values which are entered for “Ki” (the Integral Gain setting) ... not sure whether or not this is a part of the problem that you’re debugging - but thought I’d mention it just in case the PIDs are acting “flakey” from time to time ... basic idea: if the PID is not properly executed on a “time critical” basis, then it will sometimes appear to “detune” itself as the processor’s scan time varies ... note: failure to properly “trigger” the PID instruction is USUALLY done by a programmer who is more familiar with the SLC/Micro platform ... with those, the PID USUALLY takes care of its own “timed execution” action with a built-in “trigger” ... the PLC-5 and CLX don’t work the same way - so programmers who are familiar with the SLC/Micro platform often “drop a stitch” when they first start working with PID control for the other platforms ... good luck with your project ...

Share this post


Link to post
Share on other sites
Hi Ron - No, the problem I was looking for was a single fault message that had 3 causes. I hate guessing when I'm debugging outside in the freezing cold & wind so I used the printout to find each item that could cause the fault. Turned out that 2 of the 3 were at fault. A linkage had frozen & broke, a sparkplug wasn't firing well, and an air in-take filter was clogged (which wasn't on the list of things to look at, but happened to be the last key to make it restart). It's been working well for 18 months so I think the PIDs are ok in this case, but I'll look at them when my RSL5000 arrives. It runs 24/7 to burn off VOCs so the temperatures are steady-state after initial startup. The system should be constant & slow to move when a change does happen. Thanks to everyone! I couldn't have debugged it as fast as I did without you guys!

Share this post


Link to post
Share on other sites
Greetings Susan ... just a quick note ... if the PIDs are working OK, then I don’t recommend that you “fix” them ... specifically, if you were to modify the program to provide the recommended “trigger” action, then the PIDs would definitely need a MAJOR retuning ... that could run into a LOT of time consuming work - and possibly some wasted material ... survival tip: it’s hard to be a “hero” (or “heroine”) when you take something that was already working - and then “fix” it so that it doesn’t work well at all ... the concepts that I mentioned earlier are covered in two posts which begin with this one ... be sure to read the second post about “Bubba’s Paycheck” ... the “adjust-the-hourly-pay” trick is what is happening with the PIDs in your program ... specifically, using a VERY small Integral setting is being used to “compensate” for the VERY rapid (every scan) execution rate of the PID ... like I said, if it’s working OK, then think AT LEAST twice before changing anything ... just make a mental note that if the PIDs ever do start to act “flakey” then this is one of the first places to begin looking for the problem ...

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!


Register a new account

Sign in

Already have an account? Sign in here.


Sign In Now
Sign in to follow this  
Followers 0