B&B Electronics MESR9xx Manual De Usuario

•  For a Class D network (IP addresses 224.0.0.0 through 239.255.255.255) and 

Class E Networks (IP addresses 240.0.0.0 through 255.255.255.255) the subnet 
mask is ignored. 

•  MESR9xxModbus Gateways come from the factory with a default subnet mask 

value of: 255.255.255.0 

 

TCP (Transmission Control Protocol) provides reliable connection-oriented network 
communication with error checking. In TCP mode the Modbus gateway can be 
configured as a client or a server.  

When the Modbus gateway is configured as a TCP client it initiates connections with a 
server on the network. You must set up the IP address and port number of the server that 
you want the client (Modbus gateway) to communicate with. You also select whether the 
Modbus gateway is to connect at power up or only when it receives data from the device 
connected to its serial port.  

When the Modbus gateway is configured as a TCP server it waits for connections to be 
initiated by another network device. You must set up the TCP port number that it will 
listen to for connections and set the maximum (up to eight) number of simultaneous 
connections it will accept. You can filter the connections it will accept based on specific 
IP addresses or ranges of IP addresses that you specify.