Emerson Exchange 365

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RESTORING PARAMETERS AFTER POWER FAILURE

We used the RET function block to control the operation of two dryers. Each dryer is expected to operate for a number of hours before switching to the second dryer. The operation is seamless with the present configuration. My challenge is when there is power failure or controller download, the RET blocks reset to zero thereby interrupting the sequence.

We've checked the "Restore parameter values after restart" check box yet the problem persist.

Kindly assist with suggestion on how to solve this problem. 

Thank you

Moses Sawa

• 9 Jun 2016 7:10 AM
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6 Replies

• Rachelle McWright

  

  • 21 Jun 2016 7:51 PM

  Hi Moses~ Is this question related to the DeltaV application? If so, I'll move it to that group where I hope you will get a quicker response. :)

  Best Regards,

  Rachelle McWright: Business Development Manager, Dynamic Simulation: U.S. Gulf Coast

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• David Nelson

  

  • 23 Jun 2016 7:05 PM

  For power failures, the "Restore parameter values after restart" checkbox on the module property page only covers certain parameters on blocks, such as a PID block (there is an extensive list of the covered parameters in Books On-line). For parameters added to a module - such as Input Parameters - there is an separate checkbox that needs to be selected on the Parameter Properties page.
  
  For downloads, select "Preserve user-defined and critical block values" on the module property page.

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• Moses Sawa

  

  • 24 Jun 2016 3:38 PM

  In reply to David Nelson:

  Dear David,
  
  Thank you for your reply. Kindly confirm the RET FB have the capability to retain its accumulated time after a power failure.
  That is my challenge.
  
  Thank you

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• Matt Stoner

  

  • 24 Jun 2016 3:59 PM

  In reply to Moses Sawa:

  David indicated the information is in Books Online, find it under (v13 but others should be same):
  Configuration -> General Configuration -> Controller considerations -> Preserving configuration and controller data during power loss -> Restore parameter values after restart operation.

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• Moses Sawa

  

  • 25 Jun 2016 5:13 AM

  Dear David,

  
  

  Thank you for your reply. Kindly confirm the RET FB  have the capability to retain its accumulated time after a power failure.

  That is my challenge.

  
  

  Thank you 
  
  
  Sent from Yahoo Mail for iPhone
  
  

  On Thursday, June 23, 2016, 20:07, David Nelson <bounce-David_Nelson@emersonexchange365.com> wrote:

  Update from Emerson Exchange 365 David Nelson For power failures, the "Restore parameter values after restart" checkbox on the module property page only covers certain parameters on blocks, such as a PID block (there is an extensive list of the covered parameters in Books On-line). For parameters added to a module - such as Input Parameters - there is an separate checkbox that needs to be selected on the Parameter Properties page. For downloads, select "Preserve user-defined and critical block values" on the module property page. View online   You received this notification because you subscribed to the forum.  To unsubscribe from only this thread, go here. Flag this post as spam/abuse.

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• chris williams

  

  • 25 Jun 2016 5:13 AM

  Could you have a CALC block copy the accumulated time on a periodic basis to a parameter that is stored in the non-volatile memory?    Same calc block can use the SYSSTAT function to detect a power failure recovery and re-initialize the RET accumulated value from the parameter.

   

  The parameter should have the following set…

  

   

  Mr. Chris Williams – Controls Technology

  DAK Americas LLC, CA site

   

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