Controlling SEW VFD via Modbus RS485 with PLC S7-1200

Hello everyone,

I am currently working on a project where I need to control a SEW EURODRIVE motor using its variable frequency drive (VFD) via Modbus RS485 communication. I’m using a Siemens S7-1200 PLC and have configured theMB_MASTERblock in TIA Portal to communicate with the VFD.

My goal is to send commands for forward, reverse, and stop to the VFD. However, I am struggling to identify the correct addresses for these actions in theMB_MASTERblock.

Here’s what I’m looking for:

• MB_ADDR: The correct Modbus address for the VFD.

• MODE: The communication mode.

• DATA_ADDR: The Modbus register addresses to write for the forward, reverse, and stop commands.

• DATA_LEN: The length of the data to write.

I have consulted the "MOVILINK Protocol_Modbus RS485" (https://x0.at/pYY7.pdf) documentation, but I am having difficulty determining which addresses to use for these actions and whether they are bits or HEX registers.

I’ve also attached screenshots of my ladder diagrams to give an idea of the current setup.

I tried to issue a right rotation command based on the documentationon page 4, which indicates that 4000hex = +100% for right rotation. I attempted this in writing mode by setting MODE = 1 and DATA_ADDR = 4000hex (16384 in decimal) + 400001 = 4163845, as shown in the attached screenshot.

Could you please confirm if this approach is correct?

Has anyone had experience configuring and controlling SEW EURODRIVE motors via Modbus RS485 with Siemens PLCs? Any guidance or insights would be greatly appreciated!

Thanks in advance for your help.

MovimotD communication is not Modbus. It's based on RS485.The communication is based on MOVILINK Protocoll, also know as SEW SBUS.  You can buy a Profinet gateway module for the MovimotD and get the drive directly to your hardware config.

You should read the MovimotD manual, to get the whole concept.