B&B Electronics VESR321_ML_SL - Manual User Manual
Page 11
Setup and Connections
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This section describes how to setup and connect VESR321 family serial servers.
Note: In this sec
tion devices to be connected to the serial server’s serial connection are simply
referred to as the “serial device”.
Connecting the Power Supply
Connect a DC power supply to the power terminals on the top of the serial server. Polarity of the
wires is indicated adjacent to the power connectors. Acceptable voltage range is 10 VDC to 48
VDC.
Connecting VESR321 Family Serial Servers to Serial Devices
VESR321 family 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 4-wire 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 (full duplex) operation the connection supports 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.