AT&T 7500 series, 7100 series, 2500 series, 7200 series, 7400 series manual Scf, Scb, Sba, Sbb, Sca

E-2LEAD DEFINITIONS

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			Table E-1.EIA RS-232C (V.28) LEADS/DEFINITIONS
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⎜ PIN		⎜	EIA	⎜	CCITT	⎜	LEAD DESCRIPTION	⎜
⎜		⎜		⎜		⎜		⎜
⎜ NO.		⎜	INTERCHANGE	⎜	EQUIVALENT	⎜	(FUNCTION)	⎜
⎜		⎜	CIRCUIT	⎜	CIRCUIT	⎜		⎜
⎜	1	⎜	AA	⎜	101	⎜ Protective Ground		⎜
⎜	2	⎜	BA	⎜	103	⎜	Transmitted Data	⎜
⎜	3	⎜	BB	⎜	104	⎜	Received Data	⎜
⎜		⎜		⎜		⎜		⎜
⎜	4	⎜	CA	⎜	105	⎜	Request to Send	⎜
⎜	5	⎜	CB	⎜	106	⎜ Clear to Send		⎜
⎜	6	⎜	CC	⎜	107	⎜ Data Set Ready		⎜
⎜	7	⎜	AB	⎜	102	⎜	Signal Ground/Common Ground	⎜
⎜	8	⎜	CF	⎜	109	⎜	Received Line Signal Detected	⎜
⎜		⎜		⎜		⎜		⎜
⎜	9	⎜	—	⎜	—	⎜	Reserved for Testing,	⎜
⎜		⎜		⎜		⎜ (+P) Transmit Current Loop Data		⎜
⎜ 10		⎜	—	⎜	—	⎜ Reserved for Testing		⎜
⎜	11	⎜	SA	⎜	—	⎜	Supervisory Transmitted Data,	⎜
⎜		⎜		⎜		⎜	(–P) Transmit Current Loop Data	⎜
⎜		⎜		⎜		⎜		⎜
⎜	12	⎜	SCF	⎜	122	⎜	Secondary Received Line Signal	⎜
⎜		⎜		⎜		⎜ Detect—(Speed Mode Indication)		⎜
⎜ 13		⎜	SCB	⎜	121	⎜ Secondary Clear to Send		⎜
⎜	14	⎜	SBA	⎜	118	⎜	Secondary Transmitted Data	⎜
⎜	15	⎜	DB	⎜	114	⎜	Transmit Signal Element Timing	⎜
⎜		⎜		⎜		⎜		⎜
⎜	16	⎜	SBB	⎜	119	⎜	Secondary Received Data	⎜
⎜ 17		⎜	DD	⎜	115	⎜ Received Signal Element Timing		⎜
⎜ 18		⎜	—	⎜	—	⎜ Normally Unassigned		⎜
⎜		⎜	CN	⎜		⎜	Make Busy/Local Loopback	⎜
⎜		⎜		⎜		⎜	+ Receive Current Loop Data	⎜
⎜		⎜		⎜		⎜		⎜
⎜	19	⎜	SCA	⎜	120	⎜	Secondary Request to Send	⎜
⎜ 20		⎜	CD	⎜	108/2	⎜ Data Terminal Ready		⎜
⎜ 21		⎜	CG	⎜	110	⎜ Signal Quality Detector		⎜
⎜		⎜	RL	⎜	140	⎜	Remote Loopback	⎜
⎜	22	⎜	CH	⎜	111	⎜	Data Signal Rate Selector	⎜
⎜		⎜		⎜		⎜		⎜
⎜		⎜	CE	⎜	125	⎜	Ring Indicator	⎜
⎜ 23		⎜	CI	⎜	112	⎜ Data Signal Rate Selector		⎜
⎜		⎜	CU	⎜		⎜ Speed Select on Originate		⎜
⎜	24	⎜	DA	⎜	113	⎜	Transmitter Signal Element Timing	⎜
⎜	25	⎜	—	⎜	—	⎜	Normally Unassigned	⎜
⎜		⎜		⎜		⎜		⎜
⎜		⎜	CM	⎜		⎜	Make Busy/Local Loopback	⎜
⎜		⎜	TM	⎜		⎜ Test Mode		⎜
⎜		⎜		⎜		⎜ – Receive Current Loop Return		⎜