Emerson Exchange 365

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Clarification for Loop Current Disparity Error for HART

For the HART_ERRORS , I have not had luck in finding what % or value of deviation between digital and analog values triggers the Loop Current Disparity Error.

Hoping someone in the group may have that info.

Appreciate it

• Loop Current Disparity
• HART_ERRORS
• HART

js

• 6 Jul 2020 8:11 PM
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3 Replies

• Lun.Raznik

  

  • 6 Jul 2020 8:33 PM

  Loop (analog) current is compared with digital valure read using HART command - it has to be within -/+ 5% of signal span and has to fail twice before it gets sets.

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• MPHymel

  

  • 6 Jul 2020 10:57 PM

  In reply to Lun.Raznik:

  We saw this before on analog signals that are so noisy that the HART value could never "keep up" and match. We turn off analog disparity in such cases.

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• js

  

  • 7 Jul 2020 1:38 PM

  In reply to Lun.Raznik:

  Appreciate it, I just could not find this :) Though there is always a little error between digital value(mostly also on local display) and the analog value as read into deltav, hopefully this will help identify possible failures.

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