3Com Router 3012 Installation Manual page 59

X.21 DCE Cable Pinouts
Figure 34 X.21 DTE Cable Assembly
Table 35 describes X.21 DTE cable pinouts.
Table 35 X.21 DTE Cable Pinouts
DB50 Signal
7 GND
23 DTE/DCE
50 GND
10 RTS/CTS+
34 RTS/CTS-
38 CTS/RTS+
14 CTS/RTS-
20 RXD/TXD+
44 RXD/TXD-
15 TXD/RXD+
39 TXD/RXD-
19 RXC/TXCE+
43 RXC/TXCE-
- Shielding sheath <-->
Figure 35 illustrates the X.21 DCE cable.
Figure 35 X.21 DCE Cable Assembly
Table 36 describes X.21 DCE cable pinouts.
Table 36 X.21 DCE Cable Pinouts
DB50 Signal
7 GND
50 GND
10 RTS/CTS+
34 RTS/CTS-
38 CTS/RTS+
Signal Direction Signal
<--> Circuit GND
- Circuit GND
<--> Shield GND
-> Control+
-> Control-
<- Indication+
<- Indication-
<- Receiver+
<- Receiver-
-> Transmit+
-> Transmit-
<- Timing+
<- Timing-
Shielding sheath
Signal Direction Signal
<--> Circuit GND
<--> Shield GND
-> Indication+
-> Indication-
<- Control+
Serial Port Cable 59
DB15
8
8
1
3
10
5
12
4
11
2
9
6
13
-
DB15
8
1
5
12
3