RACOM M!DGE3, Руководство пользователя

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MRU (Maximum Reception Unit) — an incoming frame is closed at this size even if the stream of
bytes continues. Consequently, a permanent data stream coming to a COM results in a sequence
of MRU-sized frames sent over the network.
Note
1. Very long frames (>800 B) require good signal conditions on the Radio channel and the
probability of a collision increases rapidly with the length of the frames. Hence if your ap-
plication can work with smaller MTU, it is recommended to use values in 200 – 400 bytes
range.
Note
2. This MRU and the MTU in Radio settings are independent, however MTU should be
greater or equal to MRU.
Flow control
List box {None; RTS/CTS}, default = "None"
RTS/CTS (Request To Send / Clear To Send) hardware flow control (handshake) between the DTE
(Data Terminal Equipment) and M!DGE3 (DCE - Data Communications Equipment) can be enabled
in order to pause and resume the transmission of data. If RX buffer of M!DGE3 is full, the CTS goes
down.
Note
RTS/CTS Flow control requires a 5-wire connection to the COM port.
Buffer flush time [ms]
Number {0 – 65535}, default = 0
This parameter can be used to prevent unwanted deadlock of the serial communication. The timer
is reset by every received or transmitted packet over the COM port. When the timer expires, the
protocol status is reset and the packet buffer is cleared. Setting parameter to 0 disables the feature.
7.1.2.2. Common Protocol parameters
Each SCADA protocol used on serial interface is more or less unique. The COM port protocol module
performs conversion to standard UDP datagrams to travel across M!DGE3 Radio network. The same
settings are valid for Terminal servers as well (for more details about TS see
Section 7.1.3, “Terminal
servers” ).
Protocol
List box {None; Transparent; Async Link; DNP3; DF1; IEC101; Mars-A; Modbus RTU; PR2000;
RDS; S3964R; SAIA S-BUS; UNI}, default = "None"
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