Communication between Beckhoff RS232 and Schneider VSD (RJ45 Serial Modbus)

Hi Guys,

I have a Beckhoff CP6607. It has 2 ethernet ports, 2 usb ports, and a serial port.

I am trying to connect it to a Scheider VSD, an Altivar 71. The Scheider has a Modbus/CanOpen port, but if I plug it in to a switch it immediately trips the power. I then gleaned from the datasheet that the RJ45/ethernet port is actually a RJ45 RS485 serial port.

So basically I am trying to connect this RS485 serial port to the Beckhoffs serial port (which I assume is rs232).

Do I have to buy a converter, or is there some way that I can connect the VSD to the PLC over ethernet and just encapsulate this within another protocol?

I don't know for Beckhoff, but usually serial port on PLC is RS485. If not you can add RS485 port or use RS232 to RS485 converter. I would like to warn you to check documentation, and connect it properly as you have 10VDC on pin 7 (which you can use for converter).
For bridging modbus to Ethernet, Schneider recommends 174CEV30010, but you can also try Moxa NPort.
And at the end, to note that Altivar uses state machine, so if you want to start it you need little bit of programming.

Best regards,
Vuckovic Goran.

goghie said:

I don't know for Beckhoff, but usually serial port on PLC is RS485. If not you can add RS485 port or use RS232 to RS485 converter. I would like to warn you to check documentation, and connect it properly as you have 10VDC on pin 7 (which you can use for converter).
For bridging modbus to Ethernet, Schneider recommends 174CEV30010, but you can also try Moxa NPort.
And at the end, to note that Altivar uses state machine, so if you want to start it you need little bit of programming.

Best regards,
Vuckovic Goran.

Click to expand...

Thanks Vuckovic, I managed to get communication.

I used a RS232 to RS485 converter. It worked first time.

I will take your other recommendations into account.