Babel Buster SPX-GW, transparent pass-through gateway, is used when you simply want to convert Modbus RTU to Modbus TCP or vice versa. Access multiple RTU devices from a single TCP port, or access multiple TCP devices from a single RTU port.
RTU Devices on a TCP Network: Mapping multiple RTU devices to a single TCP IP address means the TCP port looks like a Modbus slave while the RTU port looks like a Modbus master to multiple slaves on the EIA485 link. The TCP master must provide valid unit numbers to select the different RTU devices.
TCP Devices on an RTU Network: Mapping multiple TCP devices to multiple Modbus RTU addresses means the RTU side acts as a Modbus slave while the TCP side acts as Modbus master connecting to multiple Modbus TCP slaves.
If register renumbering is needed, then the standard SPX must be used. The SPX-GW does not interpret or process any data or register numbers. The SPX-GW only processes packet source and destination.