M.2.11 Preventing malfunctions when the backlight burns out

This option defines whether or not to disable touch operations when the backlight is burned out.
[Disable]. Select this option to disable touch when the backlight is burned out, and to prevent the display unit from sending input signals to the PLC.

For models that cannot detect if the backlight is out, you cannot enable [Touch Panel Operation on Back Light Off ]. For models that support backlight burnout detection, please refer to the following.
1.5 Supported Features
On SP5000 series (excluding eXtreme Display) and GP4000 series (excluding GP-4100 series, GP-4201TM, and GP-4301TM), if the screen does not display and the status LED shows any status except the breathing LED, this indicates that the backlight is burned out. When the screen is not displayed, always check the LED status and do not run any touch operations. (Breathing LED is when the LED repeatedly and slowly turns ON and OFF.)

For details about the setting screen, refer to the setting guide.
M.17.2.2 Main Unit - Operation Settings

Go to offline mode and touch [Main Unit Settings] on the item changeover switch.
[Main Unit Settings] screen opens. Touch [Operation Settings].
[Operation Settings] screen opens. For the [Touch Panel Operation on Back Light Off] setting, select either [Operational] or [Inhibit].
- Operational
Touch operation is accepted even when the backlight burns out.
- Inhibit
Touch operation is not accepted when the backlight burns out.
[Exit] saves the changes and restarts the display unit.

Normally, the backlight burnout is detected by monitoring the backlight's current flow. However, the display unit may fail to detect this condition depending on the type of backlight problem, or the display unit may even detect the condition before the backlight burns out.

When the backlight is burned out, the Status LED is orange.
On display unit models that use two backlights, even if just one of the backlights is burned out, touch operations are disabled.
When the backlight is burned out, the System Data Area's Status bit 10^*1 turns ON.
When [Show System Menu] is set to [Lower Part] or [Upper Part], you can display the menu bar. (The screen is black, but the menu bar touch operations are enabled.)
If the backlight burns out while in offline mode, touch-panel operation is enabled, regardless of these settings.

^*1 Bit +6 (when using the Direct Access method), or bit +1 (when using the Memory Link method), turns ON