AT&T 2500 series, 7500 series, 7100 series manual Sda, Sta, Rda, Rsa, Ria, Csa, Dma, Tra, Rra, Tta

E-4LEAD DEFINITIONS

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			Table E-3.EIA RS-449 (V.24) LEADS/DEFINITIONS
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⎜ PIN		⎜	EIA	⎜	LEAD DESCRIPTION	⎜	MPDM (Note)	⎜
⎜		⎜		⎜		⎜		⎜
⎜ NO.		⎜	INTERCHANGE CIRCUIT	⎜	(FUNCTION)	⎜	INPUT/OUTPUT	⎜
⎜	1	⎜	—	⎜ Shield		⎜	—	⎜
⎜	2	⎜	SI	⎜ Signal Rate Indicator		⎜	I	⎜
⎜	3	⎜	—	⎜	Unassigned	⎜	—	⎜
⎜	4	⎜	SD(A)	⎜	Send Data	⎜	I	⎜
⎜		⎜		⎜		⎜		⎜
⎜	5	⎜	ST(A)	⎜	Send Timing	⎜	O	⎜
⎜	6	⎜	RD(A)	⎜ Receive Data		⎜	O	⎜
⎜	7	⎜	RS(A)	⎜ Request to Send		⎜	I	⎜
⎜	8	⎜	RI(A)	⎜	Receive Timing	⎜	O	⎜
⎜	9	⎜	CS(A)	⎜	Clear to Send	⎜	O	⎜
⎜		⎜		⎜		⎜		⎜
⎜	10	⎜	LL	⎜	Local Loopback	⎜	I	⎜
⎜ 11		⎜	DM(A)	⎜ Data Mode		⎜	O	⎜
⎜ 12		⎜	TR(A)	⎜ Terminal Ready		⎜	I	⎜
⎜	13	⎜	RR(A)	⎜	Receiver Ready	⎜	O	⎜
⎜	14	⎜	RL	⎜	Remote Loopback	⎜	I	⎜
⎜		⎜		⎜		⎜		⎜
⎜	15	⎜	IC	⎜	Incoming Call	⎜	O	⎜
⎜ 16		⎜	SR	⎜ Signaling Rate Selector		⎜	I	⎜
⎜ 17		⎜	TT(A)	⎜ Terminal Timing		⎜	I	⎜
⎜	18	⎜	TM	⎜	Test Mode	⎜	O	⎜
⎜	19	⎜	SG	⎜	Signal Ground	⎜	X	⎜
⎜		⎜		⎜		⎜		⎜
⎜	20	⎜	RC	⎜	Receive Common	⎜	O	⎜
⎜ 21		⎜	—	⎜ Unassigned		⎜	—	⎜
⎜ 22		⎜	SD(B) (Note)	⎜ Send Data		⎜	I	⎜
⎜	23	⎜	ST(B) (Note)	⎜	Send Timing	⎜	O	⎜
⎜	24	⎜	RD(B) (Note)	⎜	Receive Data	⎜	O	⎜
⎜		⎜		⎜		⎜		⎜
⎜	25	⎜	RS(B) (Note)	⎜	Request to Send	⎜	I	⎜
⎜ 26		⎜	RT(B) (Note)	⎜ Receive Timing		⎜	O	⎜
⎜ 27		⎜	CS(B) (Note)	⎜ Clear to Send		⎜	O	⎜
⎜	28	⎜	—	⎜	Unassigned	⎜	—	⎜
⎜	29	⎜	DM(B) (Note)	⎜	Data Mode	⎜	O	⎜
⎜		⎜		⎜		⎜		⎜
⎜	30	⎜	TR(B) (Note)	⎜	Terminal Ready	⎜	I	⎜
⎜ 31		⎜	RR(B) (Note)	⎜ Receiver Ready		⎜	O	⎜
⎜ 32		⎜	—	⎜ Unassigned		⎜	—	⎜
⎜	33	⎜	SQ	⎜	Dummy Generator ON	⎜	O	⎜
⎜	34	⎜	—	⎜	Unassigned	⎜	—	⎜
⎜		⎜		⎜		⎜		⎜
⎜	35	⎜	TT(B) (Note)	⎜	Terminal Timing	⎜	I	⎜
⎜ 36		⎜	SB	⎜ Dummy Generator OFF		⎜	O	⎜
⎜ 37		⎜	SC	⎜ Send Common		⎜	I	⎜

Note: Denotes category II or balanced circuits. All MPDM interchange circuits are implemented with RS- 423 line drivers.