M877 LSI Aircraft Time Management System
CLOCK OPERTION
Normal Operation
The SEL button selects what is to be displayed in the
four digit window and the CTL button controls what is
being displayed. Pressing select sequentially selects
GMT, Local Time, Flight Time, Elapsed Time and back
to GMT. The CTL button starts and resets Elapsed Time
when momentarily pushed. Normal operation of the
877 cannot accidentally reset time.
Setting GMT
Select GMT for display in the four digit window with the
SEL button. Simultaneously press both the select and
control buttons to enter the set mode. The tens of hours
digit will start flashing. The control button has full con-
trol of the flashing digit and each button push incre-
ments the digit. Once the tens of hour is set, the select
button selects the next digit to be set. After the last digit
has been selected and set with the control button, a
final push of the select button exits the mode. The light-
ed annunciator will resume its normal flashing, indict-
ing the GMT clock is running.
Setting LT
Select Local Time, LT, using the SEL button.
Simultaneously push the SEL and CTL buttons to enter
set mode. The tens of hours digit will start flashing. The
set operation is the same as for GMT, except that min-
utes are already synchronized with the GMT clock and
cannot be set in Local Time. The minutes are already
synchronized with GMT, but can be changed in 15 min-
ute increments for special time zones.
Control/Select Disable
When there is no aircraft power applied in the clock
CTL and SEL buttons are disabled.
Setting Flight Time Alarm
When Flight Time, FT, is displayed enter the set mode
by pressing both buttons simultaneously. The alarm
time is entered identically to GMT setting. When the
Flight Time equals the alarm the display will flash
and the alarm output activated. If FT was not being dis-
played at the time the alarm becomes active, the clock
automatically selects FT for display. Pressing either the
SEL or CTL button turns off the alarm and zeroes the
alarm time. Flight Time is unchanged and continues
counting.
Flight Time Reset
FT must be displayed when resetting. Hold CTL down
for 3 seconds, or until 99:59 Or 99:99 appears on the
display. The digits that appear depends on how the clock
is programmed. In hour and minutes, or in hours,
tenths and hundredths. Flight Time will be zeroed upon
release of the CTL button.
Elapsed Time Count Up
Select ET for display. Pressing the CTL button will start
ET counting. Elapsed Time counts up to 59 minutes, 59
seconds, and then switches to hours and minutes. It
continues counting up to 99 hours and 59 minutes.
Pressing the CTL button again resets ET to zero.
Elapsed Time Count Down
Select ET for display and enter set mode by pressing both
buttons. The countdown timer can now be set. Entering
the time is identical to GMT time setting. When the time
is entered and the last digit is no longer flashing the clock
is ready to start the countdown. Momentarily pressing the
CTL button starts the countdown. When count reach-
es zero the displays flash and the external alarm is acti-
vated. Pressing either SEL or CTL will deactivate the
alarm. ET continues counting up.
Test Mode
Hold the SEL button down for three seconds and the
display will indicate 88:88 and activate all four annun-
ciators.
FIELD OPTION CHANGES
When changes are made the connector of the clock
must be grounded to the soldering iron or warranty
may be void.
Serial Time Data:
To change from GMT to LT, remove
case and jumper LT.
Local Time:
To change from 12 hour to 24 hour format,
hold SEL in LT mode for 5 seconds till 12 HR or 24 HR
flashes, then push CTL for desired format. Push SEL to
exit set mode.
Flight Time:
To change from recording in hours, min-
utes to recording in hours, tenths and hundredths,
remove case and jumper 99.
Battery Removal:
The battery and battery holder may
be removed permanently if the aircraft battery is con-
nected to the Keep Alive input (Pin 9). No changes in
the clock are required.
Remote Time Display:
Additional time displays can be
driven by the M877 clock. Only two wires carry the time
information to the remote display. The remote displays
have independent automatic dimming. Either GMT or
LT may be displayed. Remote display units are available
from Davtron, Inc.
STANDARD AND
OPTIONAL FEATURES
Local Time
12 or 24 hour format.
Flight Time
in standard format of hours, minutes,
(99:59) or optional format of hours, tenths and hun-
dredths up to 99:99.
Flight Time Settable Alarm
when FT
reaches programmed alarm time the display flashes
and the external alarm output is activated.
Elapsed Time Count Up
counts in minutes
and seconds up to 59 minutes and 59 seconds and
then changes to hours and minutes up tp 99 hours and
59 minutes.
Elapsed Time Count Down
may be set to
count down anywhere from one second to 59 minutes
and 59 seconds.
Elapsed Time Alarm
when the count down
time entered reaches zero the display flashes and the
external alarm output is activated. (Optional)
Serial Time
output standard is GMT. (Local Time
Optional)
Voltage Input
is 28 Volts to 14 Volt.
Battery
is a longlife AA alkaline cell. The rec-
ommended change interval is two year. The clock
is available without battery from the factory. Keep
Alive (Pin 9) must then be connected to aircraft
battery. Remove AA battery if pin 9 is used.
Note
Battery can be easily removed and replaced
without removing clock from aircraft. Battery holder is
polarity marked with red end positive (+).
Greenwich Mean Time
Local Time
Flight Time
Elapsed Time
