Profibus. Profibus communications and Proxy function Block

This specification defines a set of Communication Function Blocks (Comm FB) for communication among programmable controllers and field devices over Profibus DP including DP profiles e.g. Profibus PA. These Communication Function Blocks
are defined according the international standard for programming languages of PLCs IEC 61131-3.
This specification also gives some "Guidelines for the application of the Communication Function Blocks", i.e. for implementing field device (DP slave) specific Proxy Function Blocks usable in the DP-Master PLC.