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

RJ45 Connectors

RJ45 Null-Modem
Cables (RS-232)
DeviceMaster MOD | UP Hardware Installation and Configuration Guide: 2000630 Rev. B
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.
Pin
1 RTS
2 DTR
3 Signal GND
4 TxD
5 RxD
6 DCD
7 DSR
8 CTS
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.
Signal
TxD
RxD
RTS
CTS
DSR
DCD
DTR
GND
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.
on Page 50
on Page 50
on Page 50
on Page 51
RS-232 RS-422
TxD+
Not used
Signal GND
TxD-
RxD-
Not used
Not used
RxD+
RJ45
DB9
Pins
Pins
4
2
5
3
1
8
8
7
7
4
6
1
2
6
3
5
Connecting Serial Devices
on Page 50
RS-485
TRxD+
Not used
Signal GND
TRxD-
Not used
Not used
Not used
Not used
DB25
RJ45
Pins Pins Signal
RxD
3
5
TxD
2
4
CTS
5 8
RTS
4 1
DTR
20
2
DCD
8 6
DSR
6 7
GND
7 3
Connecting Serial Devices - 49