User guide

42 - Connecting the Serial Device DeviceMaster FreeWire Installation and User Guide: 2000412 Rev. D
DB9 Null-Modem Cables
DB9 Null-Modem Cables
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.
DB9 Straight-Through Cables
Use the following figure if you need to build an RS-232 straight-through cable.
Straight-through cables are used to connect modems and other DCE devices. For
example, a straight-through cable can be used to connect COM2 of one PC to
COM2 to a modem.
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
20
5
Female
DB9
3
2
7
8
6
5
1
4
Pins
RJ45
5
4
1
3
6
7
Pins
2
8
DeviceMaster
DB9
1
2
3
4
5
8
6
7
Pins
DCD
RxD
TxD
DTR
GND
CTS
DSR
RTS
Signal
DB9
1
2
3
4
5
8
6
7
Pins
DCD
RxD
TxD
DTR
GND
CTS
DSR
RTS
Signal
Female
RI 9
9RI
RJ45
6
5
4
2
3
8
7
1
Pins
N/A
DB25
8
3
2
20
7
5
6
4
Pins
22