DeviceMaster Installation and Configuration Guide
: 2000594 Rev. F
Connecting Serial Devices - 91
Connecting Serial Devices
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)
•
•
•
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.
Pin
RS-232
RS-422
RS-485
1
RTS
TxD+
TRxD+
2
DTR
Not used
Not used
3
Signal GND
Signal GND
Signal GND
4
TxD
TxD-
TRxD-
5
RxD
RxD-
Not used
6
DCD
Not used
Not used
7
DSR
Not used
Not used
8
CTS
RxD+
Not used
Device
Ma
ster
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
Fe
ma
le
RJ45
5
4
1
3
6
7
Pins
2
8