Modbus communication with Danfoss FC 302.


Thread Starter


I want to communicate a Danfoss FC 302 VFD using Modscan 32 software by Wintech. I have set the following parameters in VFD:

Protocol: Modbus RTU
Address: 1
Baud Rate: 9600 bps
Parity: Even Parity, 1 Stop Bit

I have set the same parameters in software also and also selected the com port. But whenever I am trying to scan the slave, its showing "Modbus Time-out message". Please help me out.

My email id: [email protected]
Thanks in advance.

Bob Peterson

does your modscan work with other modbus slaves?

is the cable correct?

is the hardware interface the same on both side (both rs232 or rs485)?

If if it is rs485 is the line properly terminated?

really modbus is pretty simple. it usually just works if the cables, software, and hardware are setup right.

Everything I have repeatedly checked. I am using Adam 4561 RS485 to USB converter. But I am unable to solve the issue.
As it is a timeout signal the problem is most probabily with the connection only.

I have tried several devices including Danfoss FC102 VFD.s for modbus data with ADAM RS-485 to RS 232 converters and is working fine. Only exercise we have to do is to reverse the polarity of RS-485 connection, if required.

I strongly believe the issue is with the ADAM USB converter only.

Please try as I explained