A correctly designed alarm system is fundamental to most SCADA applications. Flexibility in the SCADA’s alarm handling is the key.
In PcVue an alarm is generated by a bit variable that has been configured with alarm behavior. This means that alarms have all the flexibility associated with a bit plus the characteristics required by an alarm. Changes in alarm value are time-stamped to millisecond resolution. The origin of the time-stamp can be PcVue itself or the source of the value (PLC, OPC etc.).
A real-time alarm list is provided by the Alarm Viewer Alarms can also be used in the HMI’s animations the same as any other variable to produce color changes, change text strings, exchange symbols etc. Individual alarms can be accepted by an operator with the corresponding user rights. Advanced group alarm acceptance strategies can be configured using SCADA Basic.
In distributed applications alarms are broadcast to all nodes. Alarm acceptance (subject to user rights) can take place on any station.
Alarm counters by level, status Domain and Nature are easily configured using specially named register variables. These can be displayed in the HMI and trigger actions (such as sending an email or generating an audible alarm) in the same way as any other variable.
Advanced alarm counters using expressions and alarm properties can be configured using a technique called alarm synthesis.