Limit Alarm

Limit alarm parameters can have subranges within the data item amplitude. Every subrange definition includes Message body that will be appended to the alarm message, the Severity of the alarm and Req. Ack. flag.

Update rate parameter defines the frequency of checking the data item value, and possibly responding with sending the alarm message.

Dead band prevents the server from generating huge amount of alarm messages and overloading the clients when the signal oscillates around one of the limits specified. Dead band value extends the limit zone. It results in sending only one alarm message even if the signal oscillates.

alarm_definitions_detail

Figure: Dialog view - limit alarm