grO whO

Control Logix/RSLogix5000 RLIM FBE rate

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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.

rlim_pics.pdf

RLIM_test.L5K

Edited by grO whO

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