Communicating S7-200 Smart PLC over modbus rtu Requisites 1. S7-200 Smart CPU ( we are using 6ES7 288-1ST20-0AA0) 2. ATV 12 AC Drive ( we are using ATV12H075M2) 3. Communication Cables Lan for PLC Programming and RJ45 to Sub D9 Male 9 Pin RS485 cable for Modbus communication between PLC and AC Drive (Pinout given below). 4. Multimeter Meco 9A06 and Screw Drivers Taparia 810 and 803. 5. Connection Wires and Power Cables, since we are using DC CPU hence 24VDC SMPS is required. Software / Manuals required 1. Step 7 Microwin Smart V2.3 for PLC Programming 2. User Manual and modbus parameters address of ATV12 ( Link below ) User Manual Modbus Parameters Address Modbus Cable Follow below given diagram to prepare cable AC Drive Setting Set below given parameters in AC Drive CtL- Fr1 Mdb Frequency command is set from modbus CHCF Sin - Not separate mode, (c