Brian,
Not sure I can help much but I will gladly share my experiences with loop
tuning from years ago. 1st, just curious what PID block you use as I have
used them all? If not one with a self-tuning algorithm (PID-A/E/X), I would
definitely recommend you replace the basic PID block with the latest version
that your software supports; PIDA being the latest and greatest version.
Each PID block has a subset of parameters basically setting up starting
values, limits, connections to external tuning blocks (the self-tuning
algorithm is in an external block; FFTUNE, FBTUNE, etc.), etc. I typically
had a basic set of starting PID values just from experience depending on the
process type; flow, pressure, temperature, level and size of tanks, pumps,
etc. Or you can use the bump option and the block will make a step change
in the output and calculate starting PID values based on the response of the
measurement. Most of the parameters are self-explanatory. I would always
start with tight limits on the PID values because I did experience some
unexpected results. When the self-tuning feature was turned on (STNREQ),
using the SELECT page I religiously watched the STATE parameter as this
feedback info gives you a good idea of what is going on and why; i.e.,
limits reached, not seeing 3-4 peaks, etc. I would continue to readjust the
starting PID values or limits based on these messages.
STATEB (if PIDA)
-3 = Pretune
-2 = Off
-1 = Hold last tuning
0 = Quiet, waiting for new (isolated) response
1 = Locating and confirming peak 1
2 = Locating and confirming peak 2
3 = Locating and confirming peak 3
4 = Locating and confirming peak 4
5 = Wait for output peak search to finish
6 = Settle (A non-isolated response can trigger a new search from this
state)
Not sure this will be of much help but it definitely requires a basic
understanding of the PID algorithm and some level of process knowledge to
start with. If your personnel are not even at this level then I suggest a
Google search on PID tuning. From memory there is a ton of info available
and I used those results to create a basic tuning class for some previous
clients. Also there are companies out there like ControlSoft, Inc.
(http://www.controlsoftinc.com) that offer specific tuning classes.
And make sure everyone understands that this tuning process is a very time
consuming effort... on each and every loop.
Good luck...
Joseph M. Riccardi
386-451-7607 Cell
Joe@xxxxxxxxxxxxx
"To give real service you must add something that cannot be bought or
measured with money; and that is sincerity and integrity." - Donald A. Adams
-----Original Message-----
From: foxboro-bounce@xxxxxxxxxxxxx [mailto:foxboro-bounce@xxxxxxxxxxxxx] On
Behalf Of Brian Long
Sent: Thursday, April 13, 2017 5:34 PM
To: foxboro@xxxxxxxxxxxxx
Subject: [foxboro] Tuning Manual
Wondered if anyone has ever seen or can recommend a good tuning procedural
manual for I/A series PID blocks? Does Foxboro do tuning classes anymore?
Thanks,
Brian
_________________________________________________________________________
This mailing list is neither sponsored nor endorsed by Schneider Electric
(formerly The Foxboro Company). Use the info you obtain here at your own
risks. See the disclaimer at www.thecassandraproject.org/disclaimer.html
foxboro mailing list: //www.freelists.org/list/foxboro
to subscribe: mailto:foxboro-request@xxxxxxxxxxxxx?subject=join
to unsubscribe: mailto:foxboro-request@xxxxxxxxxxxxx?subject=leave
_________________________________________________________________________
This mailing list is neither sponsored nor endorsed by Schneider Electric
(formerly The Foxboro Company). Use the info you obtain here at your own
risks. See the disclaimer at www.thecassandraproject.org/disclaimer.html
foxboro mailing list: //www.freelists.org/list/foxboro
to subscribe: mailto:foxboro-request@xxxxxxxxxxxxx?subject=join
to unsubscribe: mailto:foxboro-request@xxxxxxxxxxxxx?subject=leave
