Samsung SCC-C7433P Guia Del Usuario página 13

SETTING RS-A/RS- TERMINATION
As it is shown in the structure map, when Controller and RS-422A/RS-485 is connected,
it should be terminated according to the Cable feature of impedance on the each end of the
transmitting line to transfer the signals in long distance by controlling the reflection of the signals
to the lowest.
Division
TX+(DATA+)
Controller
TX-(DATA-)
Note
Termination: using numbers 1 and 2 PIN, turn to ON and it will be terminated.
RX+ RX- RX+ RX- RX+
CAM  CAM 
<RS- Half Duplex Organization>
n < 
Termination
SW-ON
RX- RX- RX+
CAM n- CAM n