3Com 3CBLSF50 - Baseline Switch 2250 - Null Modem Cable

88 APPENDIX C: PIN-OUTS
Null Modem Cable
RJ-45 to RS-232 25-pin
PC-AT Serial Cable
RJ-45 to 9-pin
Modem Cable
RJ-45 to RS-232 25-pin
Screen
TxD
RxD
Ground
RTS
CTS
DSR
DCD
DTR
Screen
RxD
TxD
Ground
RTS
DTR
CTS
DSR
DCD
Shell
3
2
5
7
8
6
1
4
1
3
2
7
4
20
5
6
8
Cable connector: RJ-45 female
PC/Terminal
Cable connector: 25-pin male/female
only required if screen
always required
required for handshake
Screen
DTR
TxD
RxD
CTS
Ground
DSR
RTS
DCD
Screen
DCD
RxD
TxD
DTR
Ground
DSR
RTS
CTS
Shell
4
3
2
8
5
6
7
1
Shell
1
2
3
4
5
6
7
8
Cable connector: RJ-45 female
PC-AT Serial Port
Cable connector: 9-pin female
only required if screen
Always required
always required
required for handshake
required for handshake
Required for handshake
Screen
TxD
RxD
RTS
CTS
DSR
Ground
DCD
DTR
Screen
TxD
RxD
RTS
CTS
DSR
Ground
DCD
DTR
Shell
3
2
7
8
6
5
1
4
1
2
3
4
5
6
7
8
20
Cable connector: RJ-45 female
RS-232 Modem Port
Cable connector: 25-pin male