Modbus TCP/IP Redundancy

[fersra 0]

Hi, Does anyone know if Modbus is able to work properly with redundant networks? I am new on this area. I want to communicate several slaves and masters PLC devices each other and every device will have 2 ethernet ports. I am concerned about detecting duplicate commands or detect disconnections of my devices. What do you suggest about it? Thanks.

[kaare_t 155]

It depends on your equipment. I have not seen a standard modbus device (PLC or other device) that supports redundancy out in the peripheral part of the network. However the "normal" way to do this is using ring switches so your core network is redundant, then use one patch from the ring switch to your specific device.