Pin Assignments
D-8 3166-A2-GB20-10November 1998
EIA-530-A-to-X.21 Cable Interface

The EIA-530-A-to-X.21 adapter cable (Figure D-5) provides the X.21 interface

shown in Table D-5.

2
14
3
16
17
9
4
19
8
10
7
24
11
2
9
4
11
6
13
3
10
5
12
8
7
14
TD-A
TD-B
RD-A
RD-B
RXC-A
RXC-B
RTS-A
RTS-B
RLSD-A
RLSD-B
SIG. COMMON
TT-A
TT-B
TD-A
TD-B
RD-A
RD-B
RXC-A
RXC-B
RTS-A
RTS-B
RLSD-A
RLSD-B
SIG. COMMON
TT-A
TT-B
530
SIGNAL DB25
PLUG DB15
SOCKET X.21
SIGNAL
495-14787

Figure D-5. EIA-530-A-to-X.21 Cable

Table D-5. X.21 Cable Interface

Signal CCITT Number Direction Pin

Signal Common 102 — 8
Transmitted Data 103 To DSU/CSU 2 (A)
9 (B)
Received Data 104 From
DSU/CSU 4 (A)
11 (B)
Request-to-Send 105 To DSU/CSU 3 (A)
10 (B)
Data Channel Received
Line Signal Detector 109 From
DSU/CSU 5 (A)
12 (B)
Transmit Signal Element
Timing (DTE Source) 113 To DSU/CSU 7 (A)
14 (B)
Receiver Signal Element
Timing (DCE Source) 115 From
DSU/CSU 6 (A)
13 (B)