Module Descriptions, RFL 9508D Digital Section
8.1.4
MULTIPLEXER/DEMULTIPLEXER BACK PLANE INTERFACE
The CM4 uses tri-state bus drivers and receivers to permit routing the demultiplexer and multiplexer
bus signals to either of two backplane buses (Bus A or Bus B). This versatile bus capability enables
simple configuration of a multiplexer as either "terminal" or "drop/insert."
Bus A/B nomenclature is used to set channel modules to transmit and receive through a desired drop-
and-insert port. In order to transmit out of drop-and-insert A, or out of a terminal shelf, a channel
module is set to operate on Bus A. In order to transmit out of drop-and-insert B, a channel module is
set to operate on Bus B. This can be seen in Figure 8-3.
TERMINAL
OR
DI/A
DI/B
CHANNEL
MODULE
SET TO
BUS B
CHANNEL
MODULE
SET TO
BUS A
Figure 8-3. The meaning of Bus A and Bus B channel module settings
RFL 9508D UCC
RFL Electronics Inc.
March 11, 2010
8-5
(973) 334-3100
