Associated with: DNP3 master outstations
The Event Buffer Overflow Alarm attribute indicates whether the outstation’s DNP3 EVENT_BUFFER_OVERFLOW IIN bit is set. This bit is set by the outstation when it has to discard events due to its internal event buffer being full. This might occur when an outstation has been offline for an extended period of time, or it is logging events too quickly and therefore its buffers are filling more quickly than expected. (Which events an outstation discards is outstation-specific. Some outstations might discard the oldest events, whereas other outstations might discard the newest events. Refer to a device’s DNP3 Profile document to determine which events it will discard.)
Having an outstation report that its EVENT_BUFFER_OVERFLOW IIN bit is set is a serious condition as it means data has been (and is still being) lost, so it is vital that the cause of the event buffer overflow is rectified as soon as possible. The problem might be due, for example, to bad configuration, a bad sensor, or communication problems. Once the problem is rectified and healthy communications are re-established, Geo SCADA Expert will upload events from the outstation until all events have been successfully uploaded.
Possible states: Displays one of the Standard Alarm States.
If the event buffer of the outstation overflows regularly, do one (or more) of the following:
- Increase the size of the outstation’s internal event buffer (see the documentation for the outstation)
- Enable the outstation to generate unsolicited messages for the event class(es) that are filling the outstation’s event buffer (see Enable Unsolicited Message Generation)
- Increase the frequency with which the Geo SCADA Expert DNP3 driver polls the outstation for the event class(es) that often cause the outstation’s event buffer to fill (see Specify When Geo SCADA Expert Performs Class Polls)
- Increase the frequency with which the Geo SCADA Expert DNP3 driver performs outstation Integrity polls (see Specify When Geo SCADA Expert Performs Integrity Polls).