Beechcraft C-12C Operator And Technical Reference Manual page 66

TM 1-1510-218-10
Pressing the EXCEEDENCE ERASE switch
for 0.2 seconds or longer will cause all
events to be erased from non-volatile
memory in all engine instruments. There is
no provision for erasing individual events
from individual system gauges.
The ITT gauges are each protected by a
1.0-ampere circuit breaker located on the pilot's left
subpanel, placarded ITT TEMP #1 and ITT TEMP #2,
Figure 2-8, Sheets 2 and 3.
b. Percentage Engine Torquemeters.
indicator displays the measured torque concurrently in
a 1 alphabetic, 3½ numeric character digital display,
and a 1-segment bar graph display.
The indicator has a digital display range of 0 to
123%. The bar graph display range is 0 to 120%.
The digital display is accurate to 1% and the bar
graph is accurate to one-half the segment resolution in
each dial scale range.
The display will contain dashes (----) when the
measured torque is greater than 124%. The dashes
will be prefixed with an "F" if an EEPROM failure has
been detected and with an "E" if an event has been
stored and not played back. The "F" display shall take
precedence over the "E" display.
The indicator has a BIT test for the LCD display,
ROM (program memory), RAM (volatile data memory),
EEPROM (non-volatile memory), and the signal input
path. The display BIT will consist of displaying all
active LCD segments for three seconds on power up.
If the RAM or ROM BIT fails the indicator display shall
be blanked. If the input signal fails BIT the indicator
shall display "0" on both the digital and bar graph
displays. BIT failures are NOT stored in EEPROM.
Once the power is cycled the display is not affected
unless the failure is again detected.
Exceedence events will be stored in EEPROM
memory. Each event record will consist of two 16-bit
words. One word will contain the peak torque
measured during the event and the other word shall
contain the event duration in seconds. A maximum of
50 events shall be recorded. If more than 50 events
are recorded, only 50 will be stored. As new events
are recorded, the oldest events shall be discarded.
The indicator will prefix the digital display with an "E"
when an event is being or has been recorded and not
played back.
The indicator digital display will start flashing
whenever indicated torque exceeds 100%.
2-50
NOTE flashing shall cease and digital torque display shall be
prefixed with an "E" when the time/torque combination
is exceeded and the indicator begins recording an
exceedance.
Event display will take precedence over normal
digital display. The bar graph will continue to display
current engine torque data.
initiated by pressing the EXCEEDENCE DISPLAY
switch for 0.2 seconds or longer. The event display
will consist of the following:
(1) The event number will be displayed for
The 2 seconds.
(2) The event peak torque percentage value
will be displayed for 2 seconds.
(3) The event duration, in seconds, will be
displayed for 2 seconds.
All three data items displayed during playback
will be prefixed with a "P" unless an EEPROM BIT
failure has been detected in which case the display will
be prefixed with an "F".
Once an event playback sequence has been
performed, the "E" prefixed to the digital display shall
be removed.
playback until the data is erased. The display will be
prefixed with an "E" again on the next power up cycle
if the old data has not been erased or if another event
is recorded.
Pressing the EXCEEDENCE ERASE switch
for 0.2 seconds or longer will cause all
events to be erased from non-volatile
memory. There is no provision for erasing
individual events.
The engine torquemeter gauges are protected by
0.5-ampere circuit breakers, placarded TORQUE
METER #1 and #2, located on the overhead circuit
breaker panel.
c. Turbine
displays the measured N
alphabetic, 3½ numeric character digital display and a
39-segment bar graph for erasing individual events.
The indicator has a digital display range of 0 to
110.0% RPM while displaying current N
199.9% RPM while displaying exceedence N
bar graph display range is 0 to 150.0% RPM.
The digital display shall contain dashes (----)
The
when the measured N
The event display is
All event data is still available for
NOTE
Tachometers. The
concurrently in a 1
1
is greater than 110.0% RPM.
1
indicator
and 0 to
1
. The
1