RACOM M!DGE2, Руководство пользователя

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is forwarded as UDP to the final destination (by default the UDP port is 8902), e.g. another M!DGE unit
with Modbus RTU device connected over the RS232 port.
Note
This behaviour comes from the RipEX functionality where UDP is a preferred transport solution.
In case of cellular networks, TCP might be a better solution. When implementing this solution
into your network, you might configure Modbus TCP on the remote M!DGE (not a unit locally
connected via Ethernet) causing the TCP session to be between a local device and remote
M!DGE instead of UDP. The final conversion from TCP to UDP so the Protocol server listening
on the UDP port 8882 by default is done at the remote unit afterwards. In such a case, make
a Translation rule which sends all received packets to the localhost.
Important
In some Modbus TCP implementations, Unit ID field within the datagram is always set to "FF".
In such a case, you can use the "Replace PLC address" option so that the Unit ID is replaced
by some Modbus RTU address. Thanks to this parameter, regular Mask/Table address
translation can be used. Consider carefully where you put the corresponding parameter (local
or remote M!DGE and if placed in Modbus TCP or Modbus RTU Protocol server menu - it can
be set at both places, but not simultaneously).
See the Application note for more details and examples.
Administrative status Enable or disable the feature.
My TCP Port The TCP port for a session with local Modbus TCP Master. It can also
be a remote Modbus TCP Master resulting in a TCP session over the
cellular network instead of UDP.
TCP inactivity [s] The TCP inactivity timeout in seconds.
M!DGE2 GPRS/UMTS/HSPA+/LTE router – © RACOM s.r.o. 130
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