Hello Lukasz,
MOELLER told me that CoDeSys has problems in LD (Ladder) editor if you have function blocks that do not start with a BOOL variable at the beginning of INPUT and OUTPUT block.
Therefore they added a dummy BOOL output to all function blocks which do not start with a BOOL. Also they added a EN variable to all input blocks. In some cases this EN input has no function (regarding to your other question)!
I hope this helps.
regards
Klaus