Pin Assignments
D-12 3162-A2-GB20-30March 1999
EIA-530-A-to-X.21 Adapter

The EIA-530-A-to-X.21 adapter (Figure D-8) provides the X.21 interface shown in

Table D-8.

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-8. EIA-530-A-to-X.21 Adapter

Table D-8. 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) 11 3 To DSU/CSU 7 (A)
14 (B)
Receiver Signal Element Timing (DCE Source) 115 From DSU/CSU 6 (A)
13 (B)