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Devicemaster lt leds, Tx/rx leds – Comtrol DeviceMaster LT User Manual

Page 129

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DeviceMaster LT User Guide: 2000586

Rev. B

Troubleshooting and Technical Support - 129

DeviceMaster LT LEDs

15. Remove the loopback plug and type abc. No characters should display because

the return path is open.

16. Re-attach the loopback plug, type abc, and the characters should appear.

17. If you want to test additional ports, simply repeat this procedure on that port

or ports.

18. Remove the loopback plug from the serial port and attach your serial device.

You may need to set the serial parameters as necessary to match your
attached equipment.

DeviceMaster LT LEDs

The DeviceMaster LT has network and port LEDs to indicate status. This
subsection discusses:

TX/RX LEDs

Network and Device LEDs

on Page 130

TX/RX LEDs

This subsection discusses RX and TX LEDS on the DeviceMaster LT.

The RX (yellow) and TX (green) LEDs function accordingly when the cable is
attached properly to a serial device.

Note: The RX/TX LEDs cycle during the reboot cycle.

The LEDs do not function as described until the port has been opened by an
application.

You can use Test Terminal to open a port or ports if you want to test a port or
ports.

The RX (green) and TX (yellow) LEDs functions are displayed in the following
table when the cable is attached properly to a serial device.

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 (Yellow)

RS-232/422/485

No data being transmitted

Always off

Data being transmitted

LED blinks