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CDPEventManager is a system for collecting and distributing events, providing events from the entire system to the user from a single point.
This document describes how to use CDPEventManager, which mainly consists of 3 component types:
- the CDPEventNode event distributor,
- the CDPEventLogger centralised event logging point,
- the CDPEventSubscriber as the programmers interface to subscribe to events in the system.
In addition, the interface IEventLogger is defined within the CDP core library to register events. Objects like the CDPAlarm use this interface to register events in the CDPEventNode instance running in the same application.
Key features for CDPEventManager:
- CDPEventNode can log events from any custom objects that reports events.
- Any custom objects can report events by implementing the IEventLogger interface.
- CDPEventLogger can log event from several event nodes and provide events from the whole distributed system in a single/redundant point in the system.
- CDPEventSubscriber can subscribe events from e.g. CDPEventLoggers, and users can do whatever they want to do with the event. E.g. store the events in event log to trace events in the system.
- All reported events are guarantied to be received by the subscriber. (As long as circular event buffer is not overloaded. If overrun occurs it is detected by the protocol and alarm is triggered.)
- Event-message protocol takes care of resending if event-message is lost in network.
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