Manual

DeviceMaster LT User Guide: 2000586 Rev. B
Connecting Serial Devices - 67
RJ45 Loopback Plugs
RJ45 Loopback Plugs
Loopback connectors are RJ45 serial port plugs with pins
wired together that are used in conjunction with application
software (Test Terminal for Windows, which is available in
PortVision DX or Minicom for Linux) to test serial ports. The
DeviceMaster LT is shipped with a single loopback plug (RS-
232/422).
•Pins 4 to 5
•Pins 1 to 8
• Pins 2 to 3 to 7
RJ45 RS-485 Test Cable
You can use a straight-through cable as illustrated previously, or build your own
cable.
Note: RS-422 pinouts are
not standardized. Each peripheral manufacturer uses
different pinouts. Refer to the documentation for the peripheral to determine
the pinouts for the signals above.
Connecting RJ45 Devices
You can use this information to connect serial devices to RJ45 connectors.
1. Connect your serial devices t
o the appropriate serial port on the DeviceMaster
L
T using the appropriate cable.
Note: Refer to the hardware
manufacturer’s installation documentation if you
need help with connector pinouts or cabling for the peripheral device.
2. Verify that the DeviceMaster LT LEDs indica
te
t
hat the devices are communicating properly.
The RX (green) and TX (yellow) LEDs functions
are
displayed in the following table when the
cable is attached properly to a serial device.
TRxD-
TRxD+
Signal
TRxD-
TRxD+
Signal
RJ45
7
5
Pins
LED Mode Description LED Status
RX (Green)
RS-232
No valid RS-232 device is connected Always off
Valid RS-232 device is connected but
no data transmission is occurring
On
Data being received LED blinks
RS-422/485
No data being received Always off
Data being received
LED blinks
No mode No mode selected Always off
TX
(Y
ellow)
RS-232/
422/485
No data being transmitted Always off
Data being transmitted LED blinks