RACOM M!DGE3, Руководство пользователя

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The PR2000 protocol is implemented in a fully transparent manner. The original protocol frames are
transported over the M!DGE3 network in their entirety.
7.1.2.3.11. Siemens 3964(R)
The 3964 protocol is utilized by the Siemens Company as a Point-to-Point connection between two
controllers. Meanwhile it has developed into an industry standard that can be found on many devices
as a universal communications interface. 3964R is the same as 3964, in addition it only uses BCC
(Block Check Character). 3964(R) handles only the link layer (L2 in OSI model), hence M!DGE3 uses
a similar way to read “SCADA address” as in UNI protocol.
There is a handshake STX(0x02) – DLE(Ox10) on the start of communication and DLE+ETX – DLE
on the end. This handshake is performed by M!DGE3 locally, it is not transferred over the M!DGE3
network.
Communication goes as follows:
LocalRTU -> STX -> LocalM!DGE3
LocalM!DGE3 -> DLE -> LocalRTU
LocalRTU -> DATA+DLE+ETX+BCC -> LocalM!DGE3
LocalM!DGE3 -> DATA -> RemoteM!DGE3*
LocalM!DGE3 -> DLE -> LocalRTU
RemoteM!DGE3 -> STX -> RemoteRTU
RemoteRTU -> DLE -> RemoteM!DGE3
RemoteM!DGE3 -> DATA+DLE+ETX+BCC -> RemoteRTU
RemoteRTU -> DLE -> RemoteM!DGE3
* only this packet is transferred over the M!DGE3 network, all the other ones are handled locally.
M!DGE3 Cellular Router – © RACOM s.r.o. 58
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