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Events and Callbacks

Execute functions triggered by specific events

You can enhance the power and flexibility of your OPC application by using event callbacks. An event is a specific occurrence that can happen while an OPC Data Access client object is connected to an OPC server. The toolbox defines a set of events that include starting, stopping, or acquiring records during a logging task, as well as events for asynchronous reads and writes, data changes, and server shutdown notification.


opccallbackEvent information for OPC callbacks
cleareventlogClear event log, discarding all events
showopceventsEvent log summary for OPC events


opcda Object PropertiesConfigure OPC DA client
dagroup Object PropertiesConfigure OPC dagroup object
daitem Object PropertiesConfigure OPC daitem object