User`s guide

SkyTrac Systems Ltd.
Document Rev. 01.007 DOC0102 Page 15 of 23
Restricted Proprietary and Confidential Information
4.4.2.1 Diagnostics Menu
The Diagnostics menu allows the user to test the display, keypad, indicators, and Buzzer
(buzzer test only applies to CDP-250 Mod-A with optional buzzer installed). All four tests
can be run in sequence by selecting the “Auto” option.
4.4.2.2 Clear Menu
The Clear menu allows the user to clear quick dials, email boxes, address book, or to clear
all data, and Reset the System to Factory defaults via the Factory Reset option.
When the CDU-250 is reset to factory settings, all the quick dials and address book entries
are erased. Also all emails in Inbox, Outbox, and Sentbox are cleared, and Brightness
configuration values are set to their factory default values.
4.4.3 Brightness Control
There are four options, selectable from the “Brightness” menu:
• Optical Sensor Mode
• Dimmer Bus Mode
• Manual Override Mode
• Configure
In Optical Sensor Mode, the CDU250 Display and Indicator brightness levels are
automatically adjusted based on the aircraft cabin ambient lighting.
In Dimmer Bus Mode the brightness levels are automatically adjusted via a cabin dimmer
bus control based on the dimmer bus voltage. This method only functions if the dimmer bus
has been wired to the CDU-250.
The Manual Override Mode overrides any previously active automatic modes (Optical
Sensor Mode or Dimmer Bus Mode) and lets the user manually adjust the brightness using
the menus or the Function Bright/Dim commands via the keypad.
4.4.3.1 Optical Sensor Brightness Mode
In optical sensor brightness mode, the CDU-250 senses the aircraft cabin ambient lighting
using the light sensor present in the Display panel and sets the brightness of the display,
indicators and backlight proportional to the aircraft cabin ambient lighting.
The Optical sensor updates the brightness only every 5-7 seconds to prevent display
flickering in varying ambient lighting conditions that are short duration.
4.4.3.2 Dimmer Bus Mode
In the Dimmer Bus Mode, the brightness of the CDU-250 backlights and LEDs will simply
follow the voltage on the dimmer bus until the voltage set by the “Dimmer Bus Volt” Menu is
reached. Afterwards, the display and backlights will remain at maximum brightness.