This is my reasoning behind the suggestion to look at OPC. it is an open connectivity protocol and most PLC's are OPC compliant (i am unaware of any that are not).
Also most PLCs are similiar to program (ladder logic is pretty common) the Fatek are prob just some generic brand of one of the much larger companies like Siemens!
The connection between plc FATEK and LinuxMCE is exactly I´m trying to do. Did you consider use of a serial connection? Did you use a interface like a relay in the outputs of the PLC?