Query filter

From TwinCAT 3.1 Build 4024.17 The filters described here are available from version TwinCAT 3.1 Build 4024.17.

When processing messages such as receiving, the question arises as to which messages are to be considered at the corresponding point.

An API is provided to formulate the desired messages. For all incoming messages, the API describes which ones are relevant, resulting in a filter.

This API is available for use in various places:

• Receiving messages in real-time via the Listener interface.
• Receiving messages which occur based on EtherCAT emergency messages of the I/O system.
• Deleting messages from the cache.
• Exporting messages to a file ("CSV Export“).

The actual use of the filters is shown in the samples Example filter and Example Listener.

The function block FB_TcEventFilter is the entry point in terms of use.