Chapter 2 15
RS-485 Receiver Biasing
RS-485 Receiver Biasing
can be implemented from the
XTRALINK IP
if the network does not supply it. Remove the two side-cover screws of
the
XTRALINK IP
, slide the cover off and re-position the bias jumpers
(shown open in the figure below) to enable biasing (shorting).
Figure 10. Internal Setting to Select RS-485 Bias
N
N
o
o
t
t
e
e
:
:
(For more information on RS-485 Receiver Biasing, see XantechRS-
422/485 Application Note available at
www.xantech.com
)
16 Chapter 2
XTRALINK IP Serial Port Connector Pin-outs
Pin-outs for RS-232, RS-422 and RS-485 operation are shown below.
DB-9M
Pin
RS-232
Signal Name
DTE RS-422 RS-485
1
Carrier Detect
DCD
In
RXDA (
−
) --
2
Receive Data
RXD
In
RXDB (+)
--
3
Transmit Data
TXD
Out
TXDB (+)
Data B (+)
4
Data Terminal Ready
DTR
Out
TXDA (
−
)
Data A (
−
)
5 Signal
Ground GND ---
GND
GND
6
Data Set Ready
DSR
In
CTSA (
−
) --
7
Request To Send
RTS
Out
CTSB (+)
--
8
Clear To Send
CTS
In
RTSB (+)
--
9
Ring Indicator
RI
In
RTSA (
−
)
Figure 11. Serial Connection Pin-outs for RS-232/RS-
422/RS-485
N
N
o
o
t
t
e
e
:
:
For more information on RS-232, RS-422 and RS-485 pin-outs, cable
connections and loopback connections refer to Appendices A, B and C