Connectors, Cables, and Pin Assignments
C-8 9664-A2-GB20-00March 2000
X.21 DTE Adapter Cable (Feature No. 3100-F1-571)
This adapter is used to connect the user data port to a DTE with an X.21 cable.
It is a 25-pin EIA-530A-to-15-pin X.21 (DB25-to-X.21) adapter cable.
98-15883
The following table provides the pin assignments for the DB25-to-X.21 adapter
cable.
Signal ITU/
CCITT #
25-Pin
Plug
Pin # Direction
15-Pin
Socket
Pin #
Transmit Data (TXD) 103 2 (A)
14 (B) To DCE 2 ( A)
9 (B)
Received Data (RXD) 104 3 (A)
16 (B) From DCE 4 (A)
11 (B )
Received Signal Element Timing
(RXC) — DCE Source 115 17 (A )
9 (B) From DCE 6 ( A)
13 (B)
Request to Send (RTS) 105 4 (A)
19 (B) To DCE 3 ( A)
10 (B)
Data Channel Received Line
Signal Detector (RLSD or LSD) 109 8 (A)
10 (B) From DCE 5 (A)
12 (B)
Transmit Signal Element/
Terminal Timing (TT) —
DTE Source
113 24 (A )
11 (B ) To DCE 7 ( A)
14 (B)
Signal Ground/Common (SG) 102 7 8