Emerson Exchange 365

DeltaV alarm Operation

1- Meaning of numbering range 12-15, 8-11, 5-7 as per snapshot above 

2- I have 3 alarm categories Safety, Environment, Asset. After Alarm Rationalization Assessment there are 3 critical alarms from each category, if these alarms trigger concurrently can we set the priority in sequence Safety ->Env -> Asset so that operator can response to Safety alarm first instead of the rest

Robin

• 26 Aug 2022 10:55 AM
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2 Replies

• Bryce Elliott

  

  • 26 Aug 2022 1:01 PM

  1. That's the Value column in DeltaV Explorer under DeltaV_System...System Configuration...Setup...Alarm Preferences...Alarm Priorities. Higher number is higher priority and will, by default, sort higher on your alarm summary page.
  2. I'm not 100% on this, but since you have a range of alarm priorities which are critical, you could make the safety alarms be priority 15, environmental be 14, and asset be 13. You would have to set them up in Alarm Priorities using the path above. After you build/modify the types, you'll have to go back in and modify the priorities of the alarms in the individual modules.

  - Bryce H. Elliott, P.E.

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• Andre Dicaire

  

  • 26 Aug 2022 4:32 PM

  In reply to Bryce Elliott:

  Bryce is correct. Originally, DeltaV used 0 to 2 for Critical, Warning and Advise alarm priorities, with 3 being Log only. For migration purposes, when the expanded alarm priority range was introduced, these were kept so that consoles could migrate and still handle these alarm priorities. So Log was kept as 3 and the new priority scheme provides 12 priorities from 15 (highest) to 4 (lowest). Most DCS in the early 2000's were introducing expanded alarm priority ranges as a feature. However, EEMUA recommendations still maintained having only three levels of alarms. So out of the box, DeltaV has three groups each with 4 priorities. Each group shares the same alarm colors. DeltaV also added the Category field to the alarms for added information to the operator.
  
  The alarm Priority should be based on the combination of consequence and time to respond. The EEMUA and now ISA18.2 discuss the expected occurrence of alarms of various priorities and set targets for acceptable frequency of occurrence. There should be very few critical alarms occurring in the system. That doesn't mean there are not many critical alarms, but through alarm rationalization, there should not be any duplication of alarms that result in alarm floods, which paralyze the operators as they cannot possible respond to all of them and often results in missed alarms that are obfuscated by the flood.
  
  If the rationalization has been effective, there should be very few critical alarms occurring, and when they do, consequential alarms should be handled to avoid the alarm flood. So maybe there is no need for these multiple priorities in the Alarm Banner. Remember that unacknowledged Advise Alarms will show as the higher importance than acknowledged warning and critical alarms. It is these lower priority alarms that can push critical alarms off the screen and cause an operator to lose sight of an active acknowledged critical alarm.
  
  But a useful reason for separating these alarms into separate priorities is that you can create Alarm Summaries specifically for these alarms. Or you could create an Alarm Summary page with several Alarm Summary objects that show Safety related alarms separate from Environmental or Asset.
  
  In the alarm banner, multiple priorities will force the order, but low priority unacknowledged Asset alarms will push Acknowledged Safety to the right and off screen if there are too many low priority. That is why it is so important to have an alarm system that does not flood and does not carry standing alarms. State based alarming helps immensely in handling those alarms that no longer matter due to a state change in the process, and help focus the operator on those issues that matter.
  
  The Alarm priorities are there to be used. But I would say that fewer active alarms through a well designed alarm system has few active alarms and is very effective with three levels of alarm granularity. We make use of multiple Alarm Priorities to group and manage non alarm conditions. The alarms are auto acknowledged and filtered from the Alarm Banner and Alarm List. They show up on dedicated alarm lists for the purpose of quickly monitoring the system of the presence of abnormal conditions such as disabled interlocks, IO blocks in Simulate or control modules with forced values.

  Andre Dicaire

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