Emerson Exchange 365

• Not Answered

alarm philosophy

Dear,

 

is it possible to configure an alarm in DCS for a manual action done by operator, from an alarm philosophy perspective. Say, an operator changes mode of controller and has to return it to its original mode but he forgets, can we configure an alarm to remind him after certain amount of time.

 

thank you for your answers/input 

Anonymous

• 8 Jun 2015 9:37 AM
• Cancel

2 Replies

• mastermadhawa

  

  • 8 Jun 2015 2:53 PM

  I am not sure if I can answer in terms of an alarm philosophy perspective in this case. But this is something that can be done. One way would be to use a simple condition block with a TIME_DURATION parameter set to the time value that you want to wait before alarming. The expression in the CND block will check for the MODE.ACTUAL != MODE.NORMAL, Assuming that your normal mode was setup as the original mode of your controller. Now you will have to create a new alarm in the controller that has the CND blocks OUT_D as the parameter to trigger the alarm on.
  
  Hope this helps.

  • Cancel
• fabuid

  

  • 14 Jun 2015 9:32 PM

  From an ANSI/ISA 18-2 perspective, it’s arguable whether an ‘alarm’ is required to indicate that a controller’s mode has been changed to something other than its ‘normal’ mode. Particularly, if the mode change is initiated manually by the Operator as part of his/her daily routine /task e.g. changing mode to facilitate routine maintenance, for example. We have something like this at one of our plants. We treat them as alerts rather than alarms. We use a specific alarm priority/category (not in use by the alarm system), prevent the alerts from appearing in both the alarm list/alarm banner and just created a dedicated ‘Offnormal’ alerts page. Part of the Operator’s task, towards the end of their shift, is to review the Offnormal alerts page for any controllers/equipment not in their normal mode. Any equipment that stays in the Offnormal page for more than one shift needs to be reported to the next, incoming shift.

  • Cancel