Instruction manual

HARDWARE DESCRIPTION
Circuit Packs
This part describes required and optional System 25 Circuit Packs (CPs) and their compatibility and
features. Required CPs are the CPU/MEM and the Service Circuit. Optional CPs are the Station
Port CPs, Trunk Port CPs, Pooled Modems, and Tone Detectors; the latter two CPs, plus the
Service Circuit, are also classified as System Resources. Table 4-B lists the CPs of System 25. For
more detailed functional descriptions of the CPs, refer to Section 3 of this manual.
Table 4-B. System Circuit Packs
CIRCUIT
NUMBER
CIRCUIT PACK
TITLE
PACK
OF
TYPE
PORTS
TN726 Data Line P 8
TN735
MET Line
P 4
TN742
Analog Line
P
8
TN746B
Analog Line
P
16
TN747B CO Trunk P 8
TN748B
Tone Detector † R 4
TN753
DID Trunk P
8
TN758
Pooled Modem † R 2
TN760B
Tie Trunk P
4
TN762B
Hybrid Line P
8
TN763
Auxiliary Trunk
P 4
TN767 DS1 Interface P
24
ZTN76 Ground Start Trunk P
8
ZTN77 Loop Start Trunk P
8
ZTN78
Tip Ring Line
P
8
ZTN79 ATL Line P
8
ZTN142 CPU/MEM C 4
ZTN84 STARLAN Interface
P
4
ZTN131 Service Circuit Clock R
4
* P = Port, C = Control, R = System Resource.
† System Resource Circuits (Tone Detector, Clock Pooled Modem, Service Circuit) ports
are internal to the system. These ports are not connected to external equipment via 25-
pair connectors.
November 1995
4-7