Emerson Exchange 365

What is ALM_HYS.

Hi,

Anyone can help me what is ALM_HYS in ALM Block.Please provide an Example for better understanding Thanks.

• alarm

obi1987

• 10 Jun 2015 7:27 PM
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1 Reply

• Alfred Pol

  

  • 11 Jun 2015 12:49 PM

  I suppose you are talking about the ALARM_HYS parameter of the function block.
  This is the hysteresis on the alarm limit to have the alarm return to normal.
  
  Suppose you have an scale of 200, a high limit at 190 and an alarm hysteresis of 5%. Then the high alarm will be active when the IN value goes above 190 and will only return to normal when the IN value goes below 190 - (5% of 200) = 180.
  
  The ALARM _HYS is to prevent alarms toggling active/inactive when the IN value stays around the alarm limit (e.g. varies between 189.9 and 190.1 in above example).

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