AT&T AT&T manual System Circuit Packs, Title Circuit Number Circuit Pack Type Ports

Table 4-B lists CPs that can be used with System 25. A description of each CP is provided in Section 3, Functional Description.

TABLE 4-B. System Circuit Packs

			TITLE		CIRCUIT	NUMBER
CIRCUIT PACK					PACK	OF
					TYPE *	PORTS
TN726	Data	Line			P	8
TN735	MET	Line			P	4
TN742	Analog		Line		P	8
TN748	Tone	Detector		†	R	4
TN753	DID	Trunk			P	8
TN758	Pooled		Modem		R	2
TN760B	Tie Trunk				P	4
TN763	Auxiliary Trunk				P	4
ZTN76	Ground Start Trunk				P	8
ZTN77	Loop	Start Trunk			P	8
ZTN78	Tip Ring Line				P	8
ZTN79	ATL	Line			P	8
ZTN81 or ZTN127	Memory				C
ZTN82 or ZTN128	Call	Processor		‡	C
ZTN84	STARLAN Interface				P	4
ZTN85	Service Circuit				R	4

* P = Port, C = Control, R = System Resource.

† System Resource Circuits (Tone Detector, Pooled Modem, Service Circuit) ports are internal to the system. These ports are not connected to external equipment via 25-pair connectors.

‡Provides four channels for the peripheral equipment of the system:

(1)System Administration Terminal

(2)SMDR Output Device

(3)Digital Tape Unit

(4)reserved for future use.

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