Loop configuration

NOTICE: The SPC42xx/43xx doesn’t support loop configuration (only 1 X-BUS port).

 

NOTICE: All expanders/keypads are fitted with a termination jumper by default. In loop configuration it’s imperative to have these jumpers fitted.

The loop (or ring) cabling method offers the highest security by providing fault tolerant communications on the X-BUS. All keypads and expanders are supervised and in case of a X-BUS fault or break, the system continues to operate and all detectors are monitored. This is achieved by connecting 1A, 1B on the controller to 2A, 2B on the first keypad or expander. The wiring continues with connection 1A, 1B to 2A, 2B on the next expander etc. to the last keypad or expander. The last connection is 1A, 1B of the last expander to 2A, 2B of the controller. See wiring configuration in the figure below.

Number	Description
1	Controller
2-4	Expanders