SCADAPack 47x & 57x Dynamic Alarms

[Mark_Pitout]

Is it possible to dynamically disable and enable alarms of a DNP3 point?

For example you want to monitor the flow from a pump. There is a "Pump_Running" digital point and a "Flow" analog point.
The flow point may have a Low alarm configured (indicates if the pipe is blocked).
However, when the pump is stopped you do not want the Flow Low alarm to be raised.
Therefore, is it possible to change the configuration of the Low alarm of the Flow Analog point during run-time to only trigger, while the Pump_Running digital point is high?

The alternative is to create a new digital point "Flow_Low", and derive the state of this point from logic, but that drives up the number of DNP3 points on the SCADA.

[Joel_Weder · Accepted solution]

Hello Mark,

The "Old School" way to do it would be to add a bit of logic, eg an AND statement that says "Low Flow AND Pump On" or similar. The configured alarm conditions (eg Under Range Limit) can be accessed in Logic Editor as part of the metadata for the analog value. This would require setting the Logic Variable Type to T_SPx70_ADV_ANALOG. But this would of course mean creating another DNP3 point, which you're trying to avoid.

BUT, after some discussion with others more knowledgeable than myself, there's a better way! Open up an object in RemoteConnect eg FlowRate, and select the Advanced tab. There's a configuration item called Event/Alert Inhibit. The state of this parameter can be set either here or in logic.

For example in logic you'd add a statement saying something like "IF PumpRun FALSE FlowRate.Alert_Inhibit" 

[AlastairF · Accepted solution]

Geo SCADA may use slightly different code for Logic.

In Remote Connect Logic Editor you would use something like this in a Structured text section.

"Flow" object  uses the Advanced Analog Logic Variable Type that allows manipulation of the Alarm within Logic.

"Pump_Running" object uses the standard BOOL Logic Variable Type.

(*disable flow alarms when pump is not running
This is simple code. In practice delays would be introduced to allow pump
to start and build pressure*)
Flow.ALERT_INHIBIT:= NOT Pump_Running.VALUE;

[Mark_Pitout]

Perfect! Thank you @Joel_Weder and @AlastairF.