Serial Gateway - Siemens SENTRON PAC4200 Manual

Description

3.12 Serial gateway

3.12 Serial gateway
SENTRON PAC4200 can be used as a serial gateway. This allows devices (slaves) that are
connected to the RS485 expansion module of PAC4200 to be connected to a device over
Ethernet (master).
Operating principle
Data sent by the master to the addressed target device: The management software
packages the serial protocol into TCP/IP packets. SENTRON PAC4200 unpacks the TCP/IP
packets and forwards the freed packets of the serial protocol to the serial port (RS485).
Data sent by the addressed target device to the master: SENTRON PAC4200 packages the
serial protocol packets into the TCP protocol and forwards the packaged user data to the
management software.
Figure 3-18
Requirements and conditions
The SENTRON PAC RS485 expansion module is required to connect the RS485 bus.
According to the RS485 bus specification, up to 31 devices can be addressed via the
gateway without special RS485 repeaters.
The management software must support the serial protocol of the addressed target device
as well as packaging/unpacking the serial protocol into/from TCP/IP.
SENTRON PAC RS485 expansion module
The slot for the SENTRON PAC RS485 expansion module is freely selectable.
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SENTRON PAC4200 as a serial gateway
SENTRON PAC4200
Manual, 09/2008, A5E02316180B-01