W&T Com-Server++, Руководство пользователя

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W&T
Box-to-Box mode
16�1 Box-to-Box application
This mode is based on a permanent TCP connection between
two serial ports on Com-Servers distributed in the network.
One of these ports acts as the master, the other as slave,
though from the view of the serial data it makes no diffe-
rence which device is acting as master or slave. The master
port functions as a TCP client and is thereby responsible for
opening (after configuration or reset) and closing (after deac-
tivating
Box-to-Box mode).
On the network side, Box-to-Box mode only exchanges
data when there are serial user data present. As long as the
keep-alive check is deactivated in the Com-Servers, there is
no acknowledgement traffic beyond the TCP protocol. (see
chapter Menu SETUP System
r
Setup TCP/IP). Optionally the
network-side connection can be encrypted via TLS.
As a consequence of the permanent connection, both Com-
Servers in a Box-to-Box connection must have fixed IP addres-
ses. It is not possible to operate using host names and URLs
with the Com-Server LC. If this is necessary – such as in con-
junction with DSL connections – the TCP client mode can be
replaced with COM-Servers of the Highspeed generation.
Typical applications
• Replacing complex serial star topology wiring, such as in
small business systems
• Serial connections over longer distances. A pair of Com-
Servers replaces two line drivers and offers in addition er-
ror correction using the Ethernet transmission procedure.
• Serial remote commection using already existing Ethernet-
Internetwork connections (routers, bridges, etc.). Confi-
dentiality of the data can be secured on the network side
through optional use of TLS/SSL.
• Implementing serial connections with frequently changing
operating sites without additional cable expenditure - sim-
ply plug into the Ethernet cable!