7.1.1 Section Network-Configuration
Various modes are available for the use of the serial interfaces:
1) TCP/IP-Server-Mode:
With this setting, the MC opens a socket in the "Listen" mode and waits for a connection on a specific port
(Local port). The MC only keeps one connection at a time. In this mode, only the port number is specified
as a parameter.
2) TCP/IP-Client-Mode:
The MC actively opens a TCP connection on the specified port of another network node. This network
node can be another MC or a computer that is waiting for a connection on the specified port. In addition to
the port number (remote port), the IP address of the communication partner must also be specified in this
mode.
3) UDP/IP-Mode:
In the UDP mode, the MC waits on the "local port" for data sent via UDP / IP. The serially received data
are sent via UDP / IP to the "remote port" of the remote IP address. If the communication partner is not
known, the remote IP address including remote port can be set to "0.0.0.0" or 0. In this case, the MC
accepts the sender IP + port information from the data packet initially arriving at the "local port".
The UDP mode should be used in those cases where e.g. A separation of the communication partners
occurs more frequently. However, it must be noted that the UDP protocol does not ensure the correct
delivery of the data.
4) Printerserver-Mode:
In print server mode, the MAC starts a TCP / IP socket in server mode that is waiting for connections on
port 9100.
5) COMSERVER-Mode:
In this mode, the MC can provide virtual COM ports on Windows®. On the PC a software product of the
company Wiesemann & Theis (www.wut.de) is used. The software tool is called COM Port redirector. The
W & T COM Port redirector, in combination with the MC, offers the possibility to address serial devices
over the network. Simply install the COM Port redirector driver for Windows® 95/98 or NT / 2000 / XP /
2003 on the PC and enter the IP address of the MC.
Please note the license conditions for the use of the COM Port redirector.
7.1.2 Section "Keep alive" settings
Once a TCP / IP connection is established, it remains until one of the communication partners closes the
connection. If the connection between the MC and the network communication partner is interrupted without
the TCP / IP connection being closed before, the MC may not reconnect. The "keep alive" function transmits
an "empty" data packet to the other at the time interval of "keep alive period". If there is no response "keep
alive probes" times, the MC resets the TCP socket and restarts the connection. Especially if the MC is
working in the TCP client mode, you should activate the "Keep alive" function by setting the values for "keep
alive period" and "keep alive probes" to values > 0.
7.1.3 Section „Handshake-Mode“
This section defines how the readiness to transmit or receive data between the serial communication
partners is handled. With the signals RTS, DTR, the MC shows receive reception. The signals CTS, DSR are
input signals via which the connected serial device shows its readiness to receive.
The MC can control the data flow remotely (remote) or autonomously (locally). The user has the following
modes to select :
1. no Handshake: the signal CTS / DSR are not evaluated. Only RTS and DTR are set active when
the serial interface is connected over the network.
2. XON / XOFF: The MC sends and receives the flow control characters XON = 0x11 and XOFF =
0x13. The MC sends an XOFF character to the serial partner when the cache in the MC is almost
full. When the cache is almost empty, the MC sends an XON character.
3. RTS / CTS: The MC controls the RTS signal to show that it is ready to receive. The MC evaluates
the signal CTS to determine the readiness of the serial partner.
4. DTR / DSR: The MC controls the DTR signal to show that it is ready to receive. The MC evaluates
the signal DSR to determine the readiness of the serial partner.
5. Remote: In this mode the MC transmits the status of the input signal lines CTS, DSR, DCD and RI to
the network communication partner. This is done via a separate socket (port). For this reason, the
user has to make further configuration depending on the network mode set.
The states of the signal lines are described as character strings. Certain letters describe the state of
a particular signal line. If the letter is capitalized, this means that the signal is active. A lowercase
MC Manual Version 2.10c
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