Table e-1. eia rs-232c (v.28) leads/definitions – AT&T DEFINITY 7200 series User Manual
Page 294

E-2
LEAD 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
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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
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