I designed 6 pieces S7-300 Plcs and MP277 HMIs.They are contolling different process and they are communicated by mpi.All of hmi have got the other hmis windows.That is operator can control system from any on hmi.(this is supplied from connections on hmi )I used SFC67 and SFC68 system blocks for data transferring between plcs.I communicated two plcs via SFC blocks but I want to communicate the other plc on the net ,no success.These blocks are called in OB35.Must it be adjusted specific parameters (master/slave),is there any parameters I forgot,I dont know,,,