PLC5/40E PID block

Christoph

Member
Christoph
Join Date
Sep 2003
Location
Indiana
Posts
345
In my program I am controlling a pump using feedback from an
E&H flowmeter. For the first time I tried using the PD file
for the PID control block. My issue is. My process variable
that I can see in the data table has a value of 5240 but if you open the PID set up dialog it has a different value
about 3243 it varies with the PV. and causes the PID to not control properly what's up with that?
🍻 TGIF
 
Post your program if you can. Zip it first. Tell us which PID instruction is in question.

Or tell us what the input range min/max are set to and the engineering unit min/max are set to in your PID configuration.
 
Last edited:
OK the input rang max=5000 input range min=0
Eng units max=5000 Eng units min=0
PV=N64:11
Tieback=N64:11 not used value=0
CV=N64:12
 
OK the input rang max=5000 input range min=0
Eng units max=5000 Eng units min=0
PV=N64:10
Tieback=N64:11 not used value=0
CV=N64:12
If I have a setpoint of 2500 my real pv is showing 3800 and the pv in the pid block screen is like 2500 (example)
So it thinks its happy! and does not bring down the output.
 
Last edited:
We are going to have to see the program when the above error occurs.

The program you posted shows a"0" in N64:10 and your PID is not being scanned.

The PID instruction should be scanned with a timer set at 1 sec (per your PID instructions
"Loop Update Time")
 

Similar Topics

P
PLC5/40E PID CV stuck at 20%
Hello I am troubleshooting a PID. My set output percentage from my SCADA is 60%. However when my PID is in manual my CV is stuck at 20%??? I can...
Replies
8
Views
3,104
Ron Beaufort
Ron Beaufort
R
PLC5-40E PID Loop
I have programmed PLC5's for several years and have attended advanced programming classes, but I still have issues with PID loops, in particular...
Replies
6
Views
3,642
jamesau
J
K
PLC5/40E PID PV & SP setup
Must the setpoint & process variable be 0-4095 in the PID instruction? Thanks for your time & patience.
Replies
3
Views
2,989
Ron Beaufort
Ron Beaufort
A
Allen Breadley PLC5/40E communication with Controllogix 1756 IO's
In one of my project, end-user wants to connect Controllogix 1756 IO's with PLC 5/40E controller on DH+ protocol. 1756 DHRIO card is installed in...
Replies
9
Views
6,718
Cody
C
J
Adding N integers to a PLC5-40E: 2000 Files
Hi everyone, I'm a Siemens expert but currently need to do a bit of AB PLC5 work. I have a PLC5/40E. I would like to know if I can add my own N...
Replies
11
Views
2,397
Mickey
Mickey
Back
Top Bottom