Cables and Pin Assignments
C-8
7985-A2-GB20-00
October 1998
Table C-5.
RS449 Cable Interface
Signal
Circuit
Mnemonic
CCITT
Number Direction
Pin
Shield
—
—
—
1
Signal Ground
SG
102A
—
19
Receive Ground
RC
102B
—
20
Send Common
SC
—
—
37
Send Data
SD
103
To DSU/CSU
4 (A)
22 (B)
Receive Data
RD
104
From DSU/CSU
6 (A)
24 (B)
Request-to-Send
RS
105
To DSU/CSU
7 (A)
25 (B)
Clear-to-Send
CS
106
From DSU/CSU
9 (A)
27 (B)
Receiver Ready
RR
109
From DSU/CSU
13 (A)
31 (B)
Data Mode
DM
107
From DSU/CSU
11 (A)
29 (B)
Terminal Ready
TR
108/1, /2
To DSU/CSU
12 (A)
30 (B)
Terminal Timing
TT
113
To DSU/CSU
17 (A)
35 (B)
Send Timing
ST
114
From DSU/CSU
5 (A)
23 (B)
Receive Timing
RT
115
From DSU/CSU
8 (A)
26 (B)
Local Loopback
LL
141
To DSU/CSU
10
Remote Loopback
RL
140
To DSU/CSU
14
Test Mode
TM
142
From DSU/CSU
18