Advantech BB-VESR9 Series, User Manual, Page: 37 / 59

VESR9xx Serial Servers
31
TCP (TRANSMISSION CONTROL PROTOCOL)
TCP (Transmission Control Protocol) provides reliable connection-
oriented network communication with error checking. In TCP mode, the
serial server can be configured as a client or a server.
When the serial server 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 (serial
server) to communicate with. You also select whether the serial server is
to connect at power up or only when it receives data from the device
connected to its serial port.
When the serial server 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 four) 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.
UDP (USER DATAGRAM PROTOCOL)
UDP (User Datagram Protocol) enables applications using UDP socket
programs to communicate with the serial ports on the serial server. UDP
protocol provides connectionless communications which allows data to
be broadcast to and received from multiple nodes on a network.
(Because it is a connectionless protocol, UDP does not guarantee the
delivery of a datagram and the datagram is only sent once.)
In UDP mode, if you want to control what network node receives data,
you must specify the IP address and UDP port that the data will be sent
to. You can choose to send to:
• Nobody
• All nodes at a specific UDP port number (called “broadcast”)
• Specific IP addresses and UDP port numbers (called “unicast”)
• A range of IP addresses and UDP port numbers (called “unicast
range”)
You can also configure the serial server to receive from nodes on the
network using the same list of configuration options.