Fast task for serial communication

Various bus systems, such as DALI, MBus or EnOcean®, are used in building automation. Many of these systems are integrated by Beckhoff hardware and are based on serial communication. Communication with the serial hardware often requires a task that is processed in a significantly shorter time than the PLC task in which the normal application runs.

In addition, the fast task must have a higher priority than the PLC task.

This relationship is well described in the Introduction to serial communication:

Within TF8040, the following components currently require a fast task for processing serial information:

• the Thies weather station, which is based on standard serial communication at 9600 bps (see Integration Thies weather station).
• the DALI function blocks, which are based on the TC3_DALI library. The integration of communication is described in the following chapter (see DALI communication).