Advantech BB-VESR9 Series, Руководство пользователя

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VESR9xx Serial Servers
10
CONNECTING VESR9XX SERIAL SERVERS TO SERIAL
DEVICES
VESR9xx Serial Servers can be configured to connect to serial devices
using RS-232, RS-422, RS-485 2-wire and RS-485 4-wire.
RS-232 connections support eight signal lines plus Signal Ground.
Signals are single ended and referenced to Ground. Default
communications parameters are 9600, 8, N, 1 and no flow control
implemented.
RS-422 connections support two signal pairs: TDA (-), TDB (+), RDA (-),
RDB (+) and GND. The data lines are differential pairs (A & B) in which
the B line is positive relative to the A line in the idle (mark) state. Ground
provides a common mode reference.
RS-485 connections support 2-wire or 4-wire operation.
When configured for 4-wire operation the connection supports two
signal pairs: TDA (-), TDB (+), RDA (-), RDB (+) and GND. This makes
full-duplex operation possible. The data lines are differential pairs (A & B)
in which the B line is positive relative to the A line in the idle (mark) state.
Ground provides a common mode reference.
When configured for 2-wire operation the connection supports one
signal pair: Data A (-) and Data B (+) signal channels using half-duplex
operation. The data lines are differential with the Data B line positive
relative to Data A in the idle (mark) state. Ground provides a common
mode reference.