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For the needs of documentation of alarms and relating activities of the D2000 system, a the term "alarm status" has been established, although actually, it is the "value of the object of the Alarm type". Alarms can be in various states, i.e. objects of Alarm type may acquire various values. An overview of the states of system alarms is shown in the following table
Condition | The condition to start the alarm |
is | has not occurred. |
| A_Alarm | Condition to start the alarm occurred. |
| A_Kvit |
Alarm | The alarm was acknowledged by an operator. |
| A_Block |
Alarm | The alarm was blocked by the operator, or the option Blocked alarm is checked in the alarm configuration. |
| A_UnBlock | The process D2000 Alarm is not running and the operator unblocked the alarm in the status A_Block (Blocked). |
| A_NoKvit | For the acknowledgement-required alarm, the condition to end the alarm was met before its acknowledgement. |
The system responds only to changes of in these states. Conditions of changes of in alarm states and activities corresponding to these changes must be defined for each object of Alarm type.
Changes
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in alarm states
| Alarm status change | Condition to change |
|---|
| Normal -> Alarm |
Condition | The condition to start the alarm must be met. The condition is represented by an object of the BOOLEAN type. Change into the state Alarm is subject to the time filter. |
| Alarm -> Acknowledged |
Operator | The operator acknowledged the alarm. |
| Alarm -> Normal |
Condition | The condition of ending an alarm must be met. If the condition is not defined, the condition of starting an alarm has to finish. If the alarm is defined as an acknowledgement-required alarm, its status may not change from the state Alarm |
into | to the state Normal |
| Acknowledged -> Normal |
Condition | The condition of ending an alarm must be met. If the condition is not defined, the condition of starting |
an | the alarm must finish. |
| Normal, Alarm, Acknowledged -> Blocked |
Operator | The operator blocked the alarm. |
| Blocked -> Normal, Alarm |
Operator | The operator unblocked the alarm. New alarm status (Normal or Alarm) depends on which state the alarm was raised in. |
| Alarm -> Unacknowledged | The condition of ending an alarm is met - for acknowledgement-required alarm. |
| Unacknowledged -> Normal |
Operator | The operator acknowledged the acknowledgement-required alarm. |
| Unacknowledged -> Alarm |
Condition | The condition of starting an alarm is met again - for acknowledgement-required alarm. |
The changes of in alarm states are shown in the following figure.
Image Modified
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