3Com Router 3000 Series - DTE Cable

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