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pushbuttons are push-push switches that alternately lock in when pushed and then release
when pushed again.
POWER (ROTARY) SWITCH
When the power switch is positioned at ON the unit is powered by the master bus. The
monitor has a provision for an external gel-cell battery (which is not installed). The BAT
position of the power switch is provided to power the unit be external battery, however, since
no external battery is provided this position makes the unit inoperative.
CLOCK MODE (ROTARY) SWITCH
The clock mode switch selects which time related function is displayed in the clock portion of
the display. The function selected can be changed using the setting pushbuttons as explained
in the following sections.
GMT - When the clock mode switch is positioned to GMT, the clock portion of the display
shows Greenwich Mean Time. The display is in a 24 hour mode and will roll over from 23
hours 59.9 minutes back to 0000.0. The smallest time division is one tenth of a minute, or six
seconds. When the clock mode switch is in this position the [10] pushbutton will advance the
hours and the [1] pushbutton will advance the m inutes. If the [10] pushbutton is held down, the
hours will continue to advance at a rate of one count per 1/2 second to the limit of 23 hours
and then roll over to zero. If the [1] pushbutton is held down, the minutes will continue to
advance at a rate of one count per ½ second to the limit of 59 minutes and then roll over to
zero (does not increment hours). The tenths of minutes is reset to zero every time a one is
added to the minutes. To accurately set the tenths, adjust the minutes using the [1]
pushbutton until the minutes equal the reference clock minutes, then when the reference clock
rolls over to the next minute, add a minute to the MONITOR. Adding the last minute will also
reset the tenths to zero, which now matches the reference clock. No other pushbutton or
pushbutton combination is effective in this mode. If the installation has provided for a direct
connection to the aircraft battery for the internal clock, proper time will always be available.
LMT - W hen the clock mode switch is positioned to LMT, the clock portion of the display
indicates Local Mean Time. The display is in a 24-hour mode and will roll over from 23 hours
59.9 minutes back to 0000.0. The smallest time division is one tenth of a minute, or six
seconds. The computer only maintains one time... GMT. To display LMT the computer
subtracts an hourly difference from GMT. When the clock mode switch is in this position, the
[10] pushbutton changes this hourly difference. If the [10] pushbutton is held down, the hours
will decrease at the rate of one count per 1/2 second until zero is reached and then roll under
to 23 hours. No other pushbutton or pushbutton combination is effective in this mode. The
hourly difference is stored in the nonvolatile memory of the unit.
TIMER - When the clock mode switch is positioned to TIMER, the clock portion of the display
shows the value of the countdown timer. The display shows only minutes in the range of zero
to 59.9. The smallest time division is one tenth of a m inute, or six seconds.
Pressing [RST] stops the timer if it was running and resets it to 0.0.
Pressing [PRE] stops the timer and sets it to the preload value of 60 mins
Pressing [ 10] will add ten minutes to the value shown.
Pressing [ l ] will add one minute to the value shown.
Pressing [. l] will add 1/10 minute (6 seconds) to the value shown.
Holding down the [ 10], [ l ], or [. l ] buttons will add it's respective value once every 1/2
second. Generally, it is usually best to reset the timer to zero by pressing [RST] and then
setting the desired count down time with the [10], [1], and [0.1] pushbuttons.
Pressing the [START] combination starts the timer counting down. The timer won't change
value for six seconds, so the audio emits a short beep to acknowledge that the computer
received the start signal. When the timer reaches 0.0 the alarm will sound and the clock
portion of the display will blink to indicate time-out. Then the timer will count up. Pressing the
[SIL/V0LT] pushbutton will silence the alarm and stop the display from blinking but the timer
will continue to run. Thereafter, every time the timer passes through zero (every hour) the
alarm will sound, until the timer is stopped. When the timer reaches 0.0 the alarm will sound
and the clock portion of the display will blink regardless where the clock mode switch is
positioned.
The timer is intended primarily as an approach timer and a fuel tank change reminder. It can
be used as an elapsed time clock (keeping in mind the 59.9 minute maximum and the alarm
when the timer goes through 0.0). Set the start time to 0.0 using the [RST] pushbuttons and
then start the timer. There is no provision for stopping the timer other than resetting back to
0.0, however. The timer value is stored in the nonvolatile memory on shutdown. However the
computer flags that indicate that the timer is running and whether up or down are not stored.
When the unit is turned back on, the timer value at tum-off is restored but the timer will be
stopped. So if your using the timer for fuel tank changes and want to maintain the timing cycle
after stopping for lunch, you merely switch the clock mode switch to TIMER and START the
timer at takeoff.
FLG TIM SETTING - When the clock mode switch is positioned to FLG TIM, the clock portion
of the display shows flight time. The display is in hours and 1/10's of hours and ranges from
0.0 to 25.5 hours. Pressing [RST] will reset the flight time readout to zero. The flight time clock
only runs when there is oil pressure, which means the engine is running.
TACH/FUEL SETTING - W hen the clock mode switch is positioned at TACH/FUEL, the clock
portion of the display shows tachometer hours. The display is in hours and 1/10's of hours and
ranges from 0.0 to 6553.5 hours. The tachtime recorded is the same tim e based on RPM as
shown on standard tachometers. No other pushbutton or pushbutton combination is effective
in this mode.
When the clock mode switch is positioned at TACH/FUEL, the setting buttons are used to
change the fuel quantity remaining since the tachometer hours are not changeable during
normal operation The fuel remaining is displayed in the GAL section of the display when the
[GPH] pushbutton is 'out'.
Pressing [RST] resets the fuel quantity to zero.