CTI Products MCN RCD System Planner - Manual (Page 46)

Appendix C System Examples
Page 42 MCN Comparator Display System Planner
7.7 Example 7 - Multi-Site Comparator Networks
Zone & Master/Slave (Sub) Comparators
Many voting systems covering a large geographic area will have comparators located at multiple sites.
In this way, comparators for particular zones are located close to their receivers, with the voted audio
brought back to the dispatch center on a single phone line for each zone. This greatly reduces the
length and cost of the associated telephone lines.
Some state-wide or city-wide systems use Master-Slave (or Sub-Comparator) systems. In these systems,
the City-Wide or State-Wide channel is broken into zones, each with its own comparator, called Slave
or Sub-Comparators. The voted audio from the Sub-comparators is brought back to a Master
comparator at the dispatch location. The Master comparator then picks the best signal from the sub-
comparators.
Figure 20 shows a way to monitor and control the comparators in a Zone or Master/Slave (Sub)
Comparator system. Each of the remote sites has its comparators connected to CIB modules on its own
MCN network. Each remote site is connected back to the central (master) site through a pair of EXB
System Extender modules. The master site has its Master Comparator connected to CIB Comparator
Interface Modules.
Since all the MCN networks are connected together at the master site, the PCs there can monitor
comparators at multiple sites simultaneously. If, for instance, a wide-area channel has 3 sub-
comparators, the PCs can monitor all 3 sub-comparators and the master comparator simultaneously.
COM 2
COM 1
HIB
HIB
T
T
OUT
IN
OUT
IN
P/S
EXB
OUT
IN
OUT
IN
P/S
CIB
CIB
OUT
OUT
IN
IN
TO LOCAL
COMPARATORS
T
P/S
CIB
CIB
OUT
OUT
IN
IN
OUT
IN
CIB
OUT
IN
T
T
P/S
CIB
CIB
OUT
OUT
IN
IN
OUT
IN
CIB
OUT
IN
T
TO COMPARATORS
TO COMPARATORS
LEASED LINES
LEASED LINES
COMPARATOR
DISPLAY
REMOTE SITE 1
REMOTE SITE N
CA-80183-100
EXB
EXB
EXB
COM 2
COM 1
COMPARATOR
DISPLAY
Figure 20 Multiple Remote Comparator Sites combined with EXB Modules
Systems using EXB System Extender Modules are considered custom designed systems. Please
contact a CTI Products application engineer for help in designing a system.