Null Modem Cable; Pc-At Serial Cable - 3Com 4500G Getting Started Manual

A

Null Modem Cable

PC-AT Serial Cable

P -
IN OUTS
RJ-45 to RS-232 25-pin
Switch 5500
Cable connector: RJ-45 female
Screen
Shell
TxD 3
RxD 2
Ground 5
RTS 7
CTS 8
DSR 6
DCD 1
DTR 4
RJ-45 to 9-pin
Switch 5500
Cable connector: RJ-45 female
Screen Shell
DTR 4
TxD 3
RxD 2
CTS 8
Ground 5
DSR 6
RTS 7
DCD 1
PC/Terminal
Cable connector: 25-pin male/female
Screen
1
3 RxD
2 TxD
7 Ground
4 RTS
20 DTR
5 CTS
6 DSR
DCD
8
PC-AT Serial Port
Cable connector: 9-pin female
Shell Screen
1 DCD
2 RxD
3 TxD
4 DTR
5 Ground
DSR
6
RTS
7
8 CTS
only required if screen
always required
required for handshake
only required if screen
Required for handshake
Always required
required for handshake
always required
required for handshake