Specifications

DeviceMaster Installation and Configuration Guide: 2000506 Rev. B Connecting Serial Devices - 61
RJ45 Serial Cables and Loopback Plugs
RJ45 Serial Cables and Loopback Plugs
You can build your own null-modem or straight-through RJ45 serial cables using the
following subsections.
RJ45 Null-Modem
Cables (RS-232)
Use the following figure if you need to build an RS-232 null-modem cable. A null-modem
cable is required for connecting DTE devices.
Note: You may want to purchase or build a straight-through cable and purchase a null-
modem adapter. For example, a null-modem cable can be used to connect COM2 of
one PC to COM2 of another PC.
Pin RS-232 RS-422 RS-485
1RTS TxD+ TRxD+
2 DTR Not used Not used
3Signal GNDNot used†Not used†
4TxD TxD- TRxD-
5RxD RxD- Not used
6 DCD Not used Not used
7 DSR Not used Not used
8CTS RxD+ Not used
† Pin 3 is tied to ground on the board, but is not used
in the cable.
DeviceMaster
TxD
RxD
RTS
CTS
DSR
GND
DCD
DTR
Signal
RxD
TxD
CTS
RTS
DTR
GND
DCD
DSR
Signal
DB9
2
3
8
7
4
5
1
6
Pins
DB25
3
2
4
7
8
6
Pins
RJ45
4
5
1
8
7
3
6
2
Pins
20
5
Female
RJ45
5
4
1
3
6
7
Pins
2
8