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Overview |
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Assign alarms |
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Choose blocking modes |
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Assign alarm priorities |
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Alarm blocking guidelines |
Monitoring and control systems do an excellent job of informing operators of problem conditions through alarms. However, there are times when operators can be overwhelmed by numerous alarms that are the result of one major problem. For example, when a process conveyor stops, it affects all machines feeding into it. The operator needs to know that the major problem is the stopped conveyor and not waste valuable time looking through all the other resulting alarms. Alarm Blocking lets you configure a hierarchy of alarms for your process so users see the important alarms first.
Alarm Blocking lets you:
Logically group alarms into
blocking groups.
Select a runtime blocking mode for
each blocking group.
Assign a priority level to each
alarm in a blocking group.
Each Alarm Blocking group works independently. This means that the high priority alarms in one group do not block the high priority alarms in another group.
Before you implement Alarm Blocking, you need to plan how you want to group and prioritize your alarms for your project. You need to decide:
The number of blocking groups you
need.
Which alarms are to be assigned to
each blocking group.
How the alarms are to be
prioritized in each blocking group.
How to handle the display of equal
priority alarms in each blocking group.
Alarms that you do not assign to Alarm Blocking groups are not affected by Alarm Blocking.
Assign alarms
CIMPLICITY software generates two types of alarms; point alarms and system alarms. Each point alarm is uniquely identified by its Alarm ID. Each system alarm is uniquely identified by its Alarm ID and Resource ID.
For example:
For point XYZ, the unique Alarm ID
is XYZ.
Each unique instance of the
$ALARM_MODIFIED system alarm is identified by the Alarm ID and the
Resource ID of the affected device.
Note: A possible exception is for
$DEVICE_DOWN. You can use the Global parameter DEVICE_DOWN_DEVICE_REF to put only the
Device ID as the alarm reference.
For Alarm Blocking, you can assign a uniquely identified alarm to only one group. This means:
You can assign a point alarm to
only one blocking group.
You can assign a uniquely
identified system alarm to only one blocking group.
This means that you can have more than one instance of a system alarm in a blocking group or you may have system alarms in more than one blocking group, provided that the Resource ID you assign to each instance is unique across all Alarm Blocking groups.
Choose blocking modes
You can select one of two blocking modes for each Alarm Blocking group that you create.
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Peer Blocking mode |
Only the first alarm in a set of alarms with equal priority displays. |
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Non-Peer Blocking mode |
All alarms in a set of alarms with equal priority display. |
Assign alarm priorities
You need to assign each alarm in an Alarm Blocking group a number from 0 to 32767. The higher the number you enter, the higher the priority of the alarm. For example, alarm XXX with priority 100 blocks alarm YYY with priority 10. You can assign the same priority number to more than one alarm in an Alarm Blocking group. The priority of an alarm and the blocking mode of the group determine whether the alarm is blocked or not.
Alarm blocking Guidelines
When an alarm that is assigned to an Alarm Blocking group is generated:
If there is a current alarm with
higher priority in the group, the newly generated alarm is
blocked.
For Peer Blocking, if there is a
current alarm with equal priority in the group, the newly generated
alarm is blocked. In other words, only one alarm in a set of alarms
with equal priority displays at any given time.
For Non-Peer Blocking, all current
alarms with equal priority display at any given time.
When the blocking alarm returns to Normal state or is deleted:
For Peer Blocking, if alarms of
equal priority exist, the oldest one displays and becomes the new
blocking alarm.
For Non-Peer Blocking, all alarms
with the next lower priority display and become the new blocking
alarms.
If lower priority alarm is the current blocking alarm and a higher priority alarm is generated, the lower priority alarm remains on the list of alarms and the higher priority alarm becomes the new blocking alarm.
If an alarm already exists in Normal state and it returns to Alarm state, the alarm is not blocked.
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Alarm blocking configuration. |
