User`s guide

SkyTrac Systems Ltd.
Document Rev. 01.007 DOC0102 Page 17 of 23
Restricted Proprietary and Confidential Information
4.4.3.4.3 Dimmer Thresh
The “Dimmer Threshold” menu provides the option to increase or decrease the threshold
voltage below which the display, backlight, and LEDs will switch to full brightness if the
sensor indicates a bright cabin (i.e. day light conditions). The value is expressed as a
percentage of the full-scale voltage, from a minimum of 0 to a maximum of 9.
Entering zero will mean that the CDP-250 will never switch to full brightness no matter how
low the voltage on the dimmer bus drops.
4.4.3.4.4 Dimmer Bus Voltage
The “Dimmer Bus Volt” provides the option to configure (increase or decrease) the dimmer
bus voltage level at which the maximum brightness level is reached. The value is
expressed as a voltage, from 1V to 35V, and should be set equal to the maximum voltage of
the aircrafts dimmer bus.
4.4.3.4.5 Maximum Night Brightness (Max Nite Bright)
Limits the maximum allowed brightness of the display under night conditions when
operating in Dimmer Bus Mode on a scale of 5 to 15. By example, a setting of 10, will limit
the brightness in night conditions to approx 66% of the maximum brightness.
4.4.4 Display Off
Select this option to turn the display off if required for certain flying conditions. Press and
hold the Enter button to turn the display back on.
**Note – This feature is not currently available and will be added to future versions.
5 ISAT EMERGENCY MODE
The ISAT Emergency mode (ISAT EMERG) is activated or cancelled (to return to Normal
“NORM” mode) via a locking toggle switch, or pushbutton switch which is located on the
DVI-250 portion of the CDU-250 front panel as described below.
Switch type Activate ISAT Emergency Cancel ISAT Emergency
Locking toggle switch
(DVI250A, DVI250C)
Place the locking toggle switch into
the “ISAT EMERG” position (up)
Place the locking toggle switch into
the “NORM” position (down)
Pushbutton switch
(DVI250AP, DVI250CP)
Press and hold the pushbutton for
a minimum of 3 seconds or longer
(while operating in Normal mode)
Press and hold the pushbutton for a
minimum of 3 seconds or longer
(when operating in Emergency mode)
For Push button switch models, the activity indicator will blink in a continuous 2 blink – 2
seconds off pattern when the ISAT Emergency mode is active.
Toggle switch models indicate the selected mode (ISAT EMERG, or NORM) via the position
and labelling above and below the locking toggle switch.
Additionally, the CDU-250 Display will indicate “ISAT EMERGENCY” on the screen.