W&T 58031, Руководство пользователя

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104
W&T
Data transfer per TCP/IP sockets
10.1 The Com-Server as TCP server
TCP is a connection-based protocol, i.e. during data
transmission there is a fixed connection between client and
server. TCP possesses all the mechanisms for opening and
closing a connection and ensuring errorless data transfer over
the network.
The connection is controlled by the user program (client
process), which opens (connect()) and closes (close()) the
connection. Once a connection is established, data can be
exchanged bidirectionally between the two processes. The
Com-Server output all the data from the LAN to the serial prot
and in return reads in all the data from the serial port in order
to convey it to your client process.
1
When there is no connection, the entry „FREE“ must
be visible in the Com-Server port menu S ETUP Port 0
r
Port State
r
Connection State . If a connection is active, the
entry „ In Use Port number <IP address> “ appears there!
10.1.1 Configuration of the local port number
To open a connection to the Com-Server, a client needs an IP
address and the TCP port number. Direct access via TCP or UDP
to the serial port of the Com-Server is done using the port
number stored in the menu branch
Setup Port 0
r
TCP/IP Mode
r
Port Number . For reasons of downward compatibility with
older firmware versions, the following port numbers are pre-
configured at the factory:
• Port A = 8000 (all models with only one serial port)
• Port B = 8100
• Port C = 8200
• Port D = 8300