Emerson Exchange 365

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Change of PID Control Action in Runtime

Is there a way of changing a "Reverse Acting" PID loop to "Direct Acting" in runtime?

I tried to write the values for above "16768" and "17792" using calc block but PID block was not happy and did not change the action

Shoaib

• PID block

snizami

• 19 Dec 2013 1:27 PM
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4 Replies

• Matt Stoner

  

  • 19 Dec 2013 1:29 PM

  You have to put the target mode of PID block to Out of Service, then write your value, and then return the PID block to the mode required.

  Regards,

  Matt

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• Jeff Swennumson

  

  • 19 Dec 2013 1:32 PM

  You first need to take the block Out of Service, switch the action, then return it to the desired mode. 

  
  Jeff Swennumson 

  PCE Pacific, Inc.

  
  On Dec 19, 2013, at 6:27 AM, "snizami" <bounce-snizami@community.emerson.com> wrote:
  
  

  Is there a way of changing a "Reverse Acting" PID loop to "Direct Acting" in runtime?

  I tried to write the values for above "16768" and "17792" using calc block but PID block was not happy and did not change the action

  • Cancel
• gamella

  

  • 19 Dec 2013 2:22 PM

  Nop, but think about it.
  Process should be one direction for a PID taking control.
  If you need something more complex then you have to implament a more complex control strategyt (maybe two PID and a selection logic)
   
  

  De: snizami [mailto:bounce-snizami@community.emerson.com]
  Enviado: Thursday, December 19, 2013 02:27 PM
  Para: DeltaV@community.emerson.com <DeltaV@community.emerson.com>
  Asunto: [EE365 DeltaV Track] Change of PID Control Action in Runtime
   
  

  Is there a way of changing a "Reverse Acting" PID loop to "Direct Acting" in runtime?

  I tried to write the values for above "16768" and "17792" using calc block but PID block was not happy and did not change the action

  • Cancel
• Jack_France

  

  • 19 Dec 2013 3:10 PM

  In reply to gamella:

  See this previous post about Reverse/Direct changing and the way to do this.

  community.emerson.com/.../5250.aspx

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