DVI-300 Installation Manual
Document Rev. 01.004
DOC0456
Page 22 of 31
Restricted Proprietary and Confidential Information
5 CONFIGURATION OF THE DVI-300
The main configuration required during installation is the brightness control configuration described below.
Additional configuration of the address book, quick dial numbers etc may be done by the user via the instructions
contained in the DVI-
300 User’s Guide.
5.1.1
DAY (BRIGHT) AND NIGHT (DIM) MODE CONFIGURATION
The DVI-300 has two brightness modes - bright (day) and dim (night) mode
– with brightness settings preset for
day-time and night-time flying conditions respectively. The DVI-300 can be wired to the aircraft dimmer bus so
that it can switch seamlessly between these modes based on the aircraft cabin lighting.
The DVI-300 monitors the pin DIM_CTRL_IN pin (pin #4) voltage to decide if it is in bright (day) or dim (night)
mode. When the voltage is below a threshold voltage called bright mode threshold, the DVI-300 is in bright mode.
When the voltage is above a threshold voltage called dim mode threshold, the DVI-300 is in dim mode. The DVI-
300 uses a hysteresis window to switch between these two modes. If the DVI-300 is in bright mode, it will switch
to dim mode only when the voltage increases above the dim mode threshold. If the DVI-300 is in dim mode, it will
switch to bright mode only when the voltage falls below the bright mode threshold.
There are two possible ways to connect the DIM_CTRL_IN (pin #4).
1.
If DIM_CTRL_IN is left unconnected, the DVI-300 will always be in bright (day) mode.
2.
If DIM_CTRL_IN is connected to the aircraft dimmer bus then the DVI-300 can switch modes based on
the aircraft dimmer bus voltage. For example when the aircraft cabin lights are off, the dimmer bus
voltage is zero and the DVI-300 goes to day (bright) mode. When the lights are ON, the dimmer bus
voltage is positive and when the voltage increases above the dim mode threshold, the DVI-300 goes to
dim (night) mode. In the night mode, the backlighting brightness of the key pad buttons follows the aircraft
dimmer bus voltage.
Table 12---- Voltage Thresholds for DIM Control Input
PARAMETER
VALUE
DIM_CTL_IN
– Max Voltage
28 Volts
Dim mode threshold
1.3 Volts
Bright mode threshold
0.7 Volts
1.
The brightness for the indicators (Send Indicator, Data delay, and Msg In) and backlighting for the keys
can be controlled separately.
UNCONTROLLED COPY IF PRINTED
