Associated with: WITS Outstations.
The Point Alarms & Events attribute is a Health Check Status item. The attribute shows whether the Field Device is inhibited so that it does not report alarms, report DNP3 events or log events.
Users can inhibit both the whole Field Device and individual points in the Field Device.
NOTE: The WITS standard refers to alarm and event inhibits as 'action inhibits'.
To inhibit an individual point in the Field Device, you use the Inhibit Alarms/Events (WITS Point) action.
To inhibit the whole Field Device, you use the Inhibit Alarms/Events (WITS Outstation) action.
If a user applies an inhibit, this will affect the behavior of the Field Device. ClearSCADA will still raise alarms and log events (if they are configured) if a point changes state. However, an inhibit may help to prevent a point from changing state.
The device profile defines the types of event the Field Device supports and therefore users can inhibit ((see Display a WITS Device Profile)).
The attribute shows the combination of events and alarms that is currently inhibited (if any). The possible states are as follows:
- Alarms, events and logged events inhibited—The Field Device will not report any point changes (that is, state, DNP3 object flag or other changes).
- Alarms and events inhibited—The Field Device will treat as logged events any point actions that are configured as alarms or events.
- Alarms inhibited—Point actions configured as alarms will behave like events. That is, the Field Device will not initiate a connection to ClearSCADA when a point changes.
- None inhibited—The Field Device performs all point actions as configured. Neither the point nor the Field Device is inhibited.
The ability to inhibit points is useful if you know that a Field Device may generate unnecessary events (for example, due to maintenance).
Users may be able to inhibit alarms and events locally at the Field Device. You will be able to see any such inhibits on your ClearSCADA Status display when the Field Device reports its status.
When you apply an inhibit by using the Inhibit Alarms/Events (WITS Outstation) action, you may also be able to apply a timeout. This is device dependent – it is defined in the device profile ((see Display a WITS Device Profile)). If you apply a timeout, the Field Device will remove the inhibit after the timeout period that you specify. It will then report the new status to ClearSCADA.
Further Information