3 Ethernet
3.1 System description
XI/ON: XNE-GWBR-2ETH-MB
10/2011 MN05002008Z-EN
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Modbus TCP
In Ethernet TCP/IP networks, Modbus TCP uses the Transmission Control Protocol (TCP) for
the transmission of the Modbus application protocol.
All parameters and data are embedded in the user data of the TCP-telegram using the encap-
sulation protocol: the client generates a special header (MBAP = Modbus Application Header),
which enables the server to clearly interpret the received Modbus-parameters and -
commands.
The Modbus protocol is thus part of the TCP/IP-protocol.
3.1.5
Checking the communication via "ping-signals"
You can check the communication between nodes in a network using ping-signals in the DOS-
prompt of your PC.
For that purpose, please enter the command "ping" and the IP address of the network node to
be checked.
If the node answers the ping-signal, it is ready for communication and takes part in the data
transfer.
Note
Chapter 5, Page 49 contains a more detailed description of Modbus TCP.
Figure 16:
ping-signal