
CWT-S1-4G Work with Scada Modbus Rtu to Tcp 4G Gateway
CWT-S1-4G Work with Scada Modbus Rtu to Tcp 4G Gateway How does Scada system read and write Modbus slave over 4G? Usually, SCADA cannot directly send Modbus message to 4G gateway, because 4G network does not provide static public IP address for simcard (except VPN), For dealing with this issue, CWT provide a Modbus TCP to RTU tool to work with Scada in server,it converts SCADA Modbus TCP to RTU message and send to 4g gateway, then 4g gateway forward Modbus RTU message to Modbus slave on RS485, So that realizes the connectivity of SCADA and remote Modbus slave over 4G. Communication process: 1). CWT 4g gateway build TCP connection with Modbus TCP to RTU toolaccording to server IP address (in this case, static public IP address or domain is necessary for server) 2). Scada system send Modbus TCP command to Modbus TCP to RTU toolaccording to salve ID (in this case, remote RS485 slave is treat as a TCP slave) 3). Modbus TCP to RTU tool convert Modbus TCP to RTU message and send to 4g g