Backlight Shutoff Detection; Backlight Shutoff Detection And External Alarm - Mitsubishi Electric GOT SIMPLE Series Operation Manual

33.4

Backlight Shutoff Detection

A GOT has a built-in backlight for the liquid crystal display.
When the GOT detects backlight shutoff, it blinks the POWER LED alternately in orange and green.
The brightness of the backlight degrades as the usage period passes. Replace the backlight when it is shut off or the display
gets blurry.
For the replacement of the backlight, contact your local distributor.
Backlight life
The usage period of the backlight can be extended by setting [Screen saving backlight off] in the GOT utility function (GOT
setup). For details, refer to the following.
Page 221 DISPLAY AND OPERATION SETTINGS (GOT SET UP)

Backlight shutoff detection and external alarm

When the GOT detects backlight shut off, the system information set in the screen design software turns on.
The information of the backlight shutoff can be output from a PLC to an external device (such as lamp and buzzer) by using
the system information.
An alarm for prevention of touch operation should be set and the external interlock should also be set for the dangerous load.
For system information details, refer the following.
GT Designer3 (GOT2000) Screen Design Manual
• Example of alarm for external devices (such as lamp and buzzer)
System information is used to output the backlight shutoff detection signal from a FX series PLC to an external
device.
Condition: The write device is D20 and all data is used (the [Select All] button on the setting screen in the
screen design software is clicked) for the system information assignment.
D36 b14: Backlight shutoff detection (System number 2-2)
This signal turns on when the backlight shutoff is detected.
This signal is used in a sequence programs shown below.
RUN monitor
M8000
Backlight shutoff detection
M34
• Caution when the backlight is shut off
Even when the backlight is shut off, the touch keys are available.
Replace the dead backlight as soon as possible.
33 MAINTENANCE AND INSPECTION
398
33.4 Backlight Shutoff Detection
MOV D36 K4M20
Y***
*indicates the output number at which the external device is connected.
Output to external device of PLC
Activated the output upon backlight
shutoff detection.