TRB255 ModBus over IP Config Problem

I am trying to get the Modbus over IP to work. My setup is that I want to access a ModBus RTU enabled device (Slave connected to TRB255) Remotely over Modbus TCP. I know that the slave is connected correctly to the TRB255, as I am able to read and write to the device over ModBus Serial Maser using the test funktion.

RS485 device configuration is enabled with the correct setting for the slave device (19200/8/1/even) and I have set up the Modbus TCP with standard port in server mode with standard port 502. I have tried different kombination of raw mode and no leading zeroes etc. but nothing seems to work. Am I missing something to complete the set up for Modbus over IP?

I am trying to acces the slave through the IP address os the TRB255.

Thanks in advance for any input.


If you are looking to access Modbus RTU slave device from outside via Modbus TCP, you need to use Modbus Over Serial Gateway feature. This way, the device will listen on specific port for Modbus TCP connections and forward them to your Modbus RTU device. There is no need to have other Modbus/Over IP features configured. I suggest following our configuration example here. You can find more information here.

Kind Regards,

Thank you so much. I will try it out.

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