Hello,
Currently RUT955 router does not have implemented ModBus RTU master functionality (which is planned in future firmware releases).
However, for now you can try to use work around solution:
- Go to Services -> RS232/RS485 -> RS485, configure serial mode "Modbus gateway" and don't forget to add allowed to connect IP address;
- Go to Services -> Modbus -> ModBus TCP master and configure slave device with router loopback IP (127.0.0.1);
This will allow you to request ModBus data from ModBus RTU device and create alarms and forward information to external servers.