Communication Task of the Protocol Stack

The internal protocol stack needs its own task to process many UDP and TCP/IP tasks. This task is created immediately when the runtime system is initialized and has priority 55, which corresponds to an IEC task priority of 23. IEC tasks with a higher priority are not influenced by UDP/TCP communication. Under some circumstances, IEC tasks with a lower priority are influenced by UDP/TCP communication.

The priority was set intentionally in order to give to the application developer the possibility not to interrupt (fieldbus) communication by lower-priority, time-consuming tasks. Or to define tasks which are more important than time-accurate communication.