Allen Bradley PowerFlex 4M AC Drive Control via Modbus-RTU 485 with Micro 850 PLC
Article No – AG22230002 : Allen Bradley VFD Control Through PLC Via Modbus.
Hello everyone! In this Article post, I would like to guide you to use Micro 850 PLC to control PowerFlex4M AC Drive.
Step-1: Micro 850 & PowerFlex 4M “Wiring Diagram”
Step-2 Setting of Modbus Communication parameter - PowerFlex 4M
In order for the VFD to be controlled via “Modbus RTU” communication, we need to configure the following minimum parameters:
Step-3 Register Control Address
Note: Micro 850 Address = “VFD Address (Dec) + 1“
>>> Motor Control Address = 8192 (Dec) + 1 = 8193
+ Set Word 8193 = 8 : Reset VFD
= 18 : Forward Run
= 34 : Reverse Run
= 1 : Stop
>>> Motor Frequency Reference Address = 8193 (Dec) + 1 = 8194
Step-4 Micro 850 Modbus RTU Settings + Channel Settings
Step-5 PLC Logic:
