MODBUS Communication with FATEK/ LS(Master K) PLC and any VFD.

Thanks. But you take it from PLC.net

RS-485 is an electrical specification defining the characteristics of the signal line-drivers and receivers in a differential-balanced, multi-node system, no communications protocol is defined.Modbus is the communication protocol that Garry suggested.I know nothing of Fatek. I assume Garry does know - or took the time to investigate the documentation of your devices - and that is why he suggested ModbusRTU.I assume that Garry has determined that ALL of your proposed devices support ModbusRTU.The first sentence in the overview that Garry linked says:Modbus RTU is an open, serial (RS-232 or RS-485) protocol derived from the Master/Slave architectureCheck your device specifications. If they all support ModbusRTU, carry on!If not, come back and let us know.If you get bogged down in the idiosyncrasies of Modbus, come back.