Intelligent RS-485 and RS-422 Adaptors
8
Jumper Options
Internally, the Intelligent RS-485 and RS-422 Adaptors are fitted with
jumpers to enable several hardware options. The photograph below
shows the circuit board inside the RS-485 adaptor, and the locations of
the jumpers are indicated by white circles with numbers next to them.
Note that the circles and numbers are not on the actual PCB, and that
this is the RS-485 adaptor – the RS-422 adaptor uses the same physical
PCB, but with different components fitted.
Jumper 1
, if fitted, connects unregulated DC voltage from the plug
pack powering the Adaptor to the RS-485 and RS-422 connectors. See
page 4 for more details.
Jumper 2
, if fitted, enables termination of the RS-422 receive input.
See page 3 for more information on termination. This jumper should
normally be fitted. Note that the RS-422 transmit output also requires
termination.
Jumper 3
, if fitted, enables the RS-485 termination resistor. See page
3 for more information on termination. This jumper should normally be
fitted.
