DCS Alarms

The DCS Alarm Screen

The DCS Alarm Screen application is launched from the menu bar (MUON -> DCS Menu, filter for Alarm Screen: Default)

The DCS Alarm Concept

• DCS parameters (states, voltages, temperatures, ...) can be defined with an OK range and one or more not-OK-ranges that trigger a DCS Alarm.
• DCS Alarms (see figure):
  
  • have a Severity: WARNING – ERROR – FATAL
  • have a Direction: CAME (alarm condition still present) or WENT (alarm gone but not acknowledged)
  • and can be of an acknowledgeable or non-acknowledgeable type

Alarm Severity, what it implies:

WARNING: Observe for a while, investigate, check if spurious reading or trend ERROR: Serious, must be investigated FATAL: Very serious, requires alerting an expert immediately

Acknowledgeable Alarms: Will stay on the alarm screen even when alarm condition is no longer present.

How to get additional information

Right clicking on an alarm item will open a sub-menu of options that will help you to try to understand the origin of the alarm.
Among the most useful options we have:

• Alarm Help: In most of the cases this option will inform you about the origin of the alarm and give you specific instructions on how to proceed.
• Trend: If the alarm is associated with a float parameter this option will allow to follow the evolution in time.
• Mask: With this option it is possible to mask the alarm. As a general rule this should be used only if instructed to do so by the expert.

DCS Alarms: What-to-do-when

In general in case of a DCS alarm, stick to the following rules

• Check for 1 or 2 minutes if the alarm disappears by itself; if yes, still mention it in your shift summary. If not,
• Check the severity of the alarm ( WARNING , ERROR , FATAL ) and check if there are specific instructions for this particular alarm by right-clicking on the alarm entry in the alarm screen and selecting Alarm Help. If a alarm help exists, follow the instructions given there. If not
  • if it is a float type value or parameter, eg temperature, fan speed or similar, check the recent history by right-clicking on the alarm item in the alarm screen and selecting Trend. If the value just fluctuates around the limit, it's enough to make a note in elog/your shift summary.
  • if it is a WARNING during the day you can call the expert on call if in doubt. If it's during the night, make an elog entry.
  • if it is a ERROR or FATAL call the expert on call, then document the alarm in elog.
• Acknowledge any alarm in WENT state only when instructed by the expert, by clicking on the red exclamation mark in the alarm screen
• Mask and alarm to temporarily remove it from the alarm screen while under investigation when instructed to do so by the expert.

-- EnricoTassi - 03-Apr-2011