Owner's manual

Section 8 - Description of Serial Server Properties Vlinx VESR4x4 Serial Server
Page 56 of 66 Manual Documentation Number: VESP211-5011m
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 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.
 VESP211serial servers 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 serial server can
be configured as a client or a server.
TCP client. 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.
TCP server. 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 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.
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 be sent once.)
 In UDP mode, if you want to control what network node receives data,
you must specify the IP address and UDP port the data will be sent to.
You can choose to send to:
 Nobody
 All nodes at a specific UDP port number. (This is called broadcast.)
 Specific IP addresses and UDP port numbers. (This is called unicast.)
 A range of IP addresses and UDP port numbers. (This is called unicast
range.)
 You can also configure the serial server to receive from nodes on the
network using the same list of configuration options.
 When the Network Protocol is set to VCOM (Virtual COM Port) the serial
server communicates over the network with a PC, acting as a remote
COM port for the computer.