Emerson Exchange 365

DTE TE_TIME_STR changed on Daylight Saving change

We have a few totalizers for production which are setup to trigger at 07:00 (TE_TIME_STR setup) with an interval of different hours.

These totalizers have been programmed this summer.

Everything was working fine until the last daylight saving change, where they changed to 06:00.

The reports were then triggered at 06:00 instead of 07:00. We had to change the TE_TIME_STR back to 07:00.

Why is it when the daylight saving rolled back one hour to normal time, the DTE time also rolled back one hour?

Pierre.

• DTE
• time string

Pierre_Dion

• 5 Nov 2015 12:55 PM
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3 Replies

• Ray Emerson

  

  • 5 Nov 2015 1:16 PM

  Pierre -
  This is a known / expected behavior of the DTE block when TE_TIME_STR and INTERVAL_STR are configured. The DTE references local time. In order to maintain the configured INTERVAL_STR, the block shifts TE_TIME_STR by the same amount as the local time has been shifted.
  
  You can workaround this by adding a CALC block that reads the current date and time, extracts out the date portion, and then appends the "T07:00:00" to the date. Write this last to the TE_TIME_STR of the DTE block, and you have effectively hard-coded the 7AM.
  
  If you have Guardian access, there is a KBA describing this behavior, and the workaround, in detail.
  
  Regards.
  Ray

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• Youssef.El-Bahtimy

  

  • 5 Nov 2015 6:19 PM

  In reply to Ray Emerson:

  The KBA in cited by Ray is AK-1000-0086.
  
  www3.emersonprocess.com/.../AK-1000-0086.pdf

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• Pierre_Dion

  

  • 6 Nov 2015 12:32 PM

  In reply to Youssef.El-Bahtimy:

  Thanks a million to all. I'll have a look and will fix it.
  Regards,
  Pierre

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