B&B Electronics Serial Servers Vlinx VESR9xx, Instruction Manual

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Serial Server Properties
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SUBNET MASK
The Subnet Mask specifies the network mask the serial server uses when on a
subnetted network.
For a Class A network (IP addresses 0.0.0.0 through 127.255.255.255) the default
subnet mask is 255.0.0.0.
For a Class B network (IP addresses 128.0.0.0 through 191.255.255.255) the default
subnet mask is 255.255.0.0
For a Class C network (IP addresses 192.0.0.0 through 233.255.255.255) the default
subnet mask is 255.255.255.0
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.
VESR9xxserial servers come from the factory with a default subnet mask value of:
255.255.255.0
TCP (TRANSMISSION CO NTROL 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 be sent once.)