Modbus RTU over UDP/IP

[MrAutomation 20]

I need to connect a ControlLogix V20 to a modbus slave device. It supports Modbus RTU over UDP. I'm fully aware of the Modbus TCP sample code from Rockwell, but this is not Modbus TCP. Does anyone know if there is a ready solution for this? There's also a Modbus RTU RS232 port on the device, so I think I'll mount a box on the wall somewhere with a Digi One IAP in it and use that, but going ethernet direct to the device would be a cleaner install if possible.

[mohssen 0]

Modbus UDP is similar to simple Modbus serial protocol. it runs on top of a TCP/IP connection and has some bytes header at the beginning of each simple modbus frame, where frame means either a request or response packet. Modbus UDP protocol is nearly identical to Modbus TCP except that it runs connectionless on UDP/IP. Unlike TCP which is a gauranteed delivery service, when using UDP the application layer is responsible for any retries required due to possible loss of frames. For connecting your Device to ControlLogix5000, you can use a Modbus RTU to EtherNet/IP converter. for example you may use GW-7472 or GW-7473 below links: http://www.icpdas-usa.com/gw_7472.html?r=mohsen http://www.icpdas-usa.com/gw_7473.html?r=mohsen If you just need Modbus TCP, then you can convert your device Modbus RTU to TCP. for example you can use tGW-712: http://www.icpdas-usa.com/tgw_712.html?r=mohsen Good Luck!

[MrAutomation 20]

Thanks for the reply. I've already decided that Modbus USP is entirely obscure and I have no idea why the company decided to use this protocol. I'm going to use a Digi One IAP, as I'm familiar with the excellent little device.