Rs-232, Rs-422, Rs-485 – Westermo Lynx-x08-F2G-S2 User Manual
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RS-232
Position
Signal
Direction
Description
No. 1
DSR
Out
Data Set Ready
No. 2
DCD
Out
Data Carrier Detect
No. 3
DTR
In
Data Terminal Ready
No. 4
SG
–
Signal Ground, not chassis ground
No. 5
RD
Out
Receive Data
No. 6
TD
In
Transmit Data
No. 7
CTS
Out
Clear To Send
No. 8
RTS
In
Request To Send
RS-422/485 (for more details see below)
Position
Signal
Direction Description
RS-422
(4-wire)
RS-485
(2-wire)
No. 1
T+
T+/R+
Out/In
RS-422: Transmit
RS-485: Transmit/Receive
No. 2
T–
T–/R–
Out/In
RS-422: Transmit
RS-485: Transmit/Receive
No. 3
R–
–
In
RS-422: Receive
No. 4
–
–
–
Not used
No. 5
–
–
–
Not used
No. 6
R+
–
In
RS-422: Receive
No. 7
–
–
–
Not used
No. 8
–
–
–
Not used
Lynx DSS is equipped with internal termination that is configurable through software
in RS-422/485 mode. The following termination schemes are supported:
RS-422
No termination
Rx
Terminate Rx
Terminate Tx
Tx
Rx
Tx
Rx
Tx
Rx
Tx
Terminate Tx and Rx
RS-485
No termination
Termination
When the unit is powered-off or during reboot, any internal termination will be
disconnected from the signal lines.
Note: Due to that the port is configurable for both RS-232 and RS-422/485,
there are no fail-safe biasing available for RS-422/485 signals.