grO whO

Control Logix/RSLogix5000 RLIM FBE rate

1 post in this topic

Posted (edited)

I am having an issue with an RLIM FBE instruction in my RSLogix5000 program.
When the 04_Position_Ctrl FBE subroutine is called every scan, the RLIM executes as expected. By this I mean if RLIM_01.IncRate is set to 1.0 and I change RLIM_01.In from 0-100 via SEL_VAR[0], it takes 100 seconds for the RLIM_01.Out to reach 100.
However, when the 04_Position_Ctrl FBE subroutine is called every 1000 mS by the S_Timer[0] timer on _00_Main rung 1, it takes a nonsensical 36 minutes and 53 seconds for RLIM_01.Out to reach 100.
I did further testing via Studio 5000 Logix Emulate, and discovered that when the S_Timer[0] timer XIC contact is not bypassed on _00_Main rung 1, it is not consistent on the ramp time.
By that I mean that it takes 36 minutes & 53 seconds to ramp from 0 to 100 one time, but the next time it takes 38 minutes & 26 seconds.

Can you please explain why this behaves in this manner, and how I can better ascertain the proper IncRate value to reach 100 within 1000 seconds instead of 100 seconds, while the S_Timer[0].DN XIC is not bypassed by DDS_OVR[0] on rung1 of _00_Main routine?
I saved the program as L5K, as attached… “RLIM_test.L5K”.
Remember that I am testing the logic with Studio 5000 Emulator.
Here are some associated screenshots.
Thanks for your help.



Edited by grO whO

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