The Analog Alarm Block generates the following alarm types, represented in the order of decreasing priority:
|
Alarm Type |
Description |
|
Other |
An alarm that is not one of those listed elsewhere in this table. Possible values include Comm (for communication errors), Over (when the blocks value is greater than the High Limit value), or Under (when the blocks value is less than the Low Limit value). |
|
High High |
A critically high alarm. |
|
Low Low |
A critically low alarm. |
|
High |
A high alarm. |
|
Low |
A low alarm. |
|
Rate of Change |
A rate of change alarm. This alarm indicates that the block's value exceeds an acceptable rate of change. |
|
Deviation |
A deviation alarm. This alarm occurs when the current value of the block varies from the Target Value field by an amount greater than the deviation alarm's value. |
NOTE: If multiple alarms occur simultaneously, the lower priority alarm type is ignored. The block closes any contacts defined for the lower priority alarms, but does not send alarms. When it detects an alarm of greater priority, the block generates an alarm and closes the digital block defined in the Contact Name field.
