Cables, Connectors, and Pin Assignments
E-10 9161-A2-GH30-30April 1998

The following table provides the pin assignments for the 25-position Sync Data

connector/interface and a DTE’s 37-position RS449 connector.

Signal ITU/

CCITT #

25-Pin

Plug

Pin # Direction

37-Pin

Socket

Pin #
Shield — 1 — 1
Transmit Data (TXD/TD ) 103 2 (A),
14 (B) To DCE 4 (A),
22 (B)
Receive Data (RXD/RD ) 104 3 ( A),
16 (B) From DCE 6 (A),
24 (B)
Request to Send (RTS) 105 4 (A ),
19 (B) To DCE 7 (A),
25 (B)
Clear to Send (CTS) 106 5 (A ),
13 (B) From DCE 9 (A),
27 (B)
Data Set Ready/Data Mode
(DSR/DM ) 107 6 From DCE 11 (A)
Signal Ground (SG) 102A 7 — 19
Data Channel Received Line
Signal Detect/Receiver Ready
(RLSD/RR )
109 8 (A),
10 (B) From DCE 13 (A),
31 (B)
Transmitter Signal Element
Timing/Transmit Timing (TXC) —
DCE Source
114 15 (A ),
12 (B) From DCE 5 (A),
23 (B)
Receiver Signal Element Timing/
Receive Timing (RXC) —
DCE Source
115 17 (A ),
9 (B) From DCE 8 (A),
26 (B)
Local Loopback (LL) 141 18 To DCE 10
Data Terminal (or DTE) Ready
(DTR/TR ) 108/1, /2 20 To DCE 12 (A)
Remote Loopback (RL) 140 21 To DCE 14
Receive Common (RC) 102B 23 — 20, 29
Transmitter Signal Element/
Terminal Timing (TT) —
DTE Source
113 24 (A ),
11 (B ) To DCE 17 (A),
35 (B)
Test Mode (TM) 142 25 From DCE 18
no connection — — — 30, 37