W&T Com-Server++, Manual

Page: 192 / 228

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W&T
Expanded services of the Com-Server
25�1 The control port
The TCP client and TCP server processes for sending data to
the serial port of the Com-Server do not allow influencing the
serial port itself. But some applications make it necessary that
the status and configuration of the port be known and capab-
le of being changed at all times.
Parallel with the data connection to the Local Port , a control
connection can be opened on the TCP controlport . Through
this connection it is possible to read out the current status
of the port (handshake lines and error states) or to despatch
commands. The user data itself is only transported through
the actual data connection.
The TCP port number of the control port is stored in the
menu branch
Setup Port x
r
TCP/IP Mode
r
Control port . The
following port numbers are pre-configured at the factory:
• Port A = 9094
• Port B = 9194
• Port C = 9294
1 The control connection can only be opened if the
Com-Server port functions as a TCP server. In Box to Box
mode this service is not available.
The data- andcontrol ports are independent of each other.
They may be individually opened and closed whenever desi-
red.
Use of the system password
If a system password has been configured (see section
Basic
Configuration of the Com-Server ), this must be null-termi-
nated ([password] + 0x00) and sent to the Com-Server via
the Control Port within 2s after a connection has been suc-
cessfully opened. If the Com-Server does not receive a correct
or even any password within this time, it sends the message
PASSWD? followed by a null byte (0x00) to the client and clo-
ses the TCP connection.