Digital Clock - Cirrus DESIGN SR20 Information Manual

Section 7 Cirrus Design
Airplane Description SR20

Digital Clock

The airplane is equipped with a 2¼" Davtron M803 digital clock
located on the left instrument panel immediately outboard of the
airspeed indicator. The clock provides Universal Time (UT), Local
Time (LT), Elapsed Time (ET), Outside Air Temperature (OAT) in ° C or
° F, and Voltmeter functions. All features and functions are selectable
from control buttons on the clock face. The clock receives the OAT
signal from a temperature sensor installed immediately forward of the
pilots door. The clock operates on 28 VDC supplied through the 5-amp
Engine Inst circuit breaker on Main Bus 1. Keep-alive power is
supplied through a 5-amp fuse connected to the airplane main
distribution bus in the Master Control Unit (MCU). A replaceable AA
battery is installed to provide up to three years battery back up.
SEL and CTL Buttons
All time keeping and set functions are addressable using the Select
and Control buttons below the time display. Upon power up the clock
will display Universal Time (UT). Pressing the Select button 3 times
will display Local Time (LT), and Elapsed Time (ET) sequentially.
Pressing the button again will return the display to UT.
Set UT or LT:
Use the Select button to select UT or LT as desired. Simultaneously
press Select and Control buttons (tens of hours LED will flash). Press
Control button repeatedly as required to increment digit to desired
value. Press Select button to select the next digit to be set. After all
digits have been set, press the Select button again to return to the
normal mode.
Flight Time (FT):
The flight time (FT) option is not available in this installation. If FT is
selected the display will 'zero.'
Elapsed Time (ET):
The ET mode may be used either in 'count-up' or in 'count-down'
modes.
To set the count-up mode:
1. Select ET using the Select button; and
7-78 P/N 13999-002 Info Manual
September 2011