The Centum VP supports Modbus/TCP and EtherNet/IP: The ICC ETH-1000 gateway can be both a Modbus/TCP and EtherNet/IP client, while simultaneously communicating via Profinet IO (with firmware update to be released on 11/10). I'm not sure whether your Siemens equipment is Profinet capable, but if it is, then the ETH-1000 can do the protocol conversion.