CP1E to Q2V over ModBus

[Dimitar026]

Hi, 

I am new to Omron, but I have quite experience with other PLCs and VFDs. I am trying to connect the CP1E-N30S PLC unit to Q2V-4007-AAA VFD over Modbus. VFD is controlling three phase asyn motor. The A- from the RS485 port from the PLC is connected to the RS485- of the VFD, B+ from the PLC to RS485+ of the VFD. Found a ladder for start and stop of the motor which seems fine and load to the PLC (change the slave address to the VFD address). Change the parameters of the VFD for controlling over Modbus and turn on all the components. 

When pressing the Lo/Re button on the VFD, on the 7-segment screen flashes CALL for once, which is error for bad Serial Communication. On the PLC side the A641 execution bit is &4 which means Modbus-RTU Master Execution Error Flag. Is there someone who can help me to establish communication, thanks in advance.

[Dimitar026]

Finally I switched to Remote control on the VFD side, now I am getting CE Alarm which stands for Modbus Communication Error. Response time is set to 10ms on each side, communication parameters are also changed to be equal on both sides. (9600, 8, 1, E) On the PLC side D1352 is 80hex = Response timeout. On the VFD side U1-19 Data length error = error and Timeout = Error.