Which command triggers an occurrence of the event immediately using the ActiveEvent control?

The choice of "InvokeEventEx('EventTagName')" is correct because this command is specifically designed to trigger an event occurrence directly within the context of the ActiveEvent control. When utilized, it allows for the immediate activation of the specified event using the tag name provided, ensuring that the event is processed in real-time.

In the context of the AVEVA Historian system and event management, this function is particularly valuable as it wraps the functionality of triggering an event in a way that is compatible with the underlying architecture of the ActiveEvent control. The command is generally intended to invoke the event handling routines expected by the system immediately, which is essential in scenarios where real-time response is critical.

In contrast, the other commands might imply similar functionalities but may not be suitable for immediate execution or are designed for different contexts within the platform. Hence, "InvokeEventEx" stands out as the precise command for triggering events instantly in the specified framework.