3Com Router 3000 Series User Manual

X.21 DTE Cable
The X.21 DTE cable has a DB15 (male) connector at the network end. Figure 11
illustrates the X.21 DTE cable.
Figure 11 X.21 DTE Cable
Tabl e 16 lists X.21 DTE cable pinouts.
15 TXCE+ -> V SCR+
16 TXCE- -> X SCR-
3 TXC+ -> Y SCT+
4 TXC- -> AA SCT-
17 RXC+ <- U SCTE+
18 RXC- ? W SCTE-
11 DCD+ -> F RLSD
22 LL <- J LL
Shielding shell Core-shielding
layer
<--> Core-shielding
layer
Shielding shell
Tabl e 16 X.21 DTE Cable Pinouts
DB28 Signal Signal direction DB15 (male) Signal
6 GND <--> 8 Circuit GND
10 MODE_DCE
9 MODE2
21 GND <--> 1 Shield GND
13 RTS+ -> 3 Control+
14 RTS- -> 10 Control -
23 CTS+ <- 5 Indication+
24 CTS - <- 12 Indication -
19 RXD+ <- 4 Receiver+
20 RXD- <- 11 Receiver+
1 TXD+ -> 2 Transmit+
2 TXD - -> 9 Transmit-
17 RXC+ ? 6 Timing+
18 RXC - <- 13 Timing -
Shielding shell Core-shieldin
g layer
<--> Core-shielding
layer
Shielding shell
Table 15 V.35 DCE Cable Pinouts (continued)
DB28 Signal Signal direction 34PIN (female) Signal
3Com Router Release Notes for V1.20
25

3Com Router 3000 Series Specifications

General

Brand	3Com
Model	Router 3000 Series
Category	Network Router
Language	English