Telephone Systems General Description

Strata CTX670 Overview
CTX670 Remote Expansion Cabinet
Strata CTX General Description 11/02 9
Expansion Cabinets
One to six Expansion Cabinets can be added to increase the system station and CO line capacity.
Each expansion cabinet provides 10 slots (S_01~S_10). Figure 5 shows an Expansion Cabinet.
Refer to the following section for cabinet slot and station/line capacities. Tables 4 and 5 show the
number of stations and CO lines allowed when additional cabinets and PCBs are used.
CTX670 Remote Expansion Cabinet
A CTX670 Expansion Cabinet can be located up to three kilometers (1.86 miles) from its Base
Cabinet. Remote Expansion Cabinets are enabled by the RRCU PCB. One RRCU connects to up
to two ribbon-type Data Cables and applies the inter-cabinet signal to a multi-mode fiber-optic
pair. One fiber pair can support one or two expansion cabinets in one remote location using one
RRCU in the Base Cabinet and another in the Remote Expansion Cabinet.
The CTX670 Base Cabinet supports up to six Remote Expansion Cabinets (at least one RRCU
PCB is required for each remote location).
Remote cabinets support the BIOU for external Page Zones, Night Bell, etc., and all CO line and
trunk interface PCBs. Network clock synchronization can only be derived from digital trunks
installed in the Base Cabinet (Master) location.
S_01 S_02 S_03 S_04 S_05 S_06 S_07 S_08 S_09 S_10
5003
CABINET NO.
2
S_01 S_02 S_03 S_04 S_05
S_06 S_07 S_08 S_09 S_10
34567
POW
+5V
-5V
P. F.
RESET
EXP
BASE
AC IN
AC IN
DC OUT
-27V1
-27V2
-27V3
-27V4
+
-
POWER
ON
OFF
FG
5002
POW
+5V
-5V
P. F.
RESET
EXP
BASE
AC IN
BATT
DC OUT
-27V1
-27V2
-27V3
-27V4
+
-
POWER
ON
OFF
FG
5002
Figure 5 Expansion Cabinet Interior