adccommunitymod (AutomationDirect) asked a question.
Created Date: May 23,2005
Created By: Brandon
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I have 5 PID loops (none cascaded) set up on a DL 450, and they have worked fine up until now. Nothing was changed in the program, and now they don't seem to respond to the DSP PID control interface. When I click the form choosing to change mode to Manual, it: - displays "Manual " - hangs for a second - displays a blank field - returns back to displaying "Automatic " No confirmation box is displayed (which I never disabled). Also on a side note: changing the bits manually (Addr+00.Bit0 or Bit1 - > ON) works fine. Only the DSP interface of the PID loops doesn't work. Any ideas? Thanks, Brandon
Created Date: May 23,2005
Created by: Brandon
I have 5 PID loops (none cascaded) set up on a DL 450, and they have worked fine up until now. Nothing was changed in the program, and now they don't seem to respond to the DSP PID control interface.
When I click the form choosing to change mode to Manual, it:
- displays "Manual "
- hangs for a second
- displays a blank field
- returns back to displaying "Automatic "
No confirmation box is displayed (which I never disabled).
Also on a side note: changing the bits manually (Addr+00.Bit0 or Bit1 -> ON) works fine. Only the DSP interface of the PID loops doesn't work.
Any ideas?
Thanks,
Brandon
Created Date: May 23,2005
Created by: bcarlton
Is it possible that the keyswitch on the CPU is in "Run ' instead of "Term "?
Created Date: May 23,2005
Created by: Brandon
All PLCs we use have always been in 'term ' the mode.
I am thinking of clearing the PLC and reloading the ladder program + PID loops as a kind of last ditch effort, if noone has any other ideas. I can only do that when the 4 connected engines are all offline, which is almost rare (at least lately). So hopefully by then another solution can be found.
If it still doesn't work, I could write out a how-to sheet explaining the process of changing bits manually as a very last resort, but that would be my last choice.
Created Date: May 23,2005
Created by: Tech Guy
You didn't mention which version and build of Directsoft you were using. If you are not using the newest version, you might try updating Directsoft here.
Created Date: May 23,2005
Created by: Brandon
DS 4.0 Build 18
I will try updating the Build now.
EDIT: Updated to DS 4.0 Build 25. PID control problem persists.
Created Date: May 26,2005
Created by: Brandon
Reloaded the program to the PLC (without clearing the entire PLC memory + scratchpad first) and it still doesn't work.
Next stop will be to clear the entire PLC (inlc. scratchpad) and see if that works. If it doesn't I guess I'm out of luck...