IDEMIA DOCUMENT
– REPRODUCTION AND DISCLOSURE PROHIBITED
RS-485 Communication
293732943-F
11
Step
three
:
c
omm
unic
at
ion
s
RS-232
from the
Com Port
RS-232 to RS-
485 converter RS-485 to
1200m (4000ft)
RS485
16
R / 485_TX/RX+ (Y)
Green / Black
18
RS422_TX- / 485_TX/RX- (Z)
Green / White
19
RS422/485_GND
Black / Red
For RS-485 installations, the cable should be run in a
daisy-chain configuration (i.e. converter > position 1 >
position 2 > position 3, etc.).
Choose one twisted pair of conductors to use for
RS-485 TX/RX+(Y) (Green / Black wire) and RS-485
TX/RX-(Z) (Green / White wire).
Another conductor should be used for Signal
Ground (Black / Red Wire) .
Use CAT-5 UTP (or better) cable (shielded recommended) with a impedance of 120
. AWG 24 should be the
minimum wire gauge used.
Choose a RS-232 to RS-485 converter that supports Sense Data to switch from Send to Receive mode.
A maximum of 31 devices may be installed on the same line.
The maximum total cable length is 4000 ft. (1200m).
The cable must be dedicated to this installation and not used for any other purpose
