Rj45 Connectors; Rj45 Null-Modem Cables (Rs-232) - Comtrol DeviceMaster DM-2000 Series Installation And Configuration Manual

RJ45 Connectors

This subsection provides the following information:
• Connector pin assignments (below)
•

RJ45 Null-Modem Cables (RS-232)

• RJ45 Null-Modem Cables (RS-422)
• RJ45 Straight-Through Cables (RS-232/485)
• RJ45 Loopback Plugs
• RJ45 RS-485 Test Cable
• Connecting RJ45 Devices
You can build your own null-modem or straight-through RJ45 serial cables if you are using the DB9 to RJ45
adapters 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.
DeviceMaster Installation and Configuration Guide: 2000594 Rev. F
on Page 92
on Page 92
on Page 92
on Page 93
Pin RS-232
1 RTS
2 DTR
3 Signal GND
4 TxD
5 RxD
6 DCD
7 DSR
8 CTS
RJ45
Signal
Pins
TxD 4
RxD 5
RTS 1
CTS 8
DSR 7
DCD 6
DTR 2
GND 3
on Page 92
RS-422 RS-485
TxD+ TRxD+
Not used Not used
Signal GND Signal GND
TxD- TRxD-
RxD- Not used
Not used Not used
Not used Not used
RxD+ Not used
DB9
DB25 RJ45
Pins
Pins
Pins
2
3
5
3
2
4
8
5 8
7
4 1
4
20
2
1
8 6
6
6
7
5
7
3
Connecting Serial Devices
Signal
RxD
TxD
CTS
RTS
DTR
DCD
DSR
GND
Connecting Serial Devices - 91