Software Monitors - Honeywell BENDIX/KING KAP 140 Maintenance Manual

2.2.2 SOFTWARE MONITORS

The following monitoring functions are implemented in the FCC software.
2.2.2.1 Acceleration Reasonability check:
For --5302, --54XX, --55XX, --77XX, --7802, --79XX versions or --5101 and --5201 units with SW
version 01/06: If the absolute difference between the current accelerometer output and the
average value for accelerometer is greater than 0.8g's for 1.0 seconds the accelerometer
reasonability check will fail and the autopilot will be disconnected. The Pitch LED will turn on and
dashes appear across the pitch coupled display field of the FCC. Engagement of the roll axis will
be allowed, but pitch axis operation will be disallowed until the excessive acceleration is removed.
This monitor runs continuously whether the autopilot is engaged or not.
Note: If after preflight test successfully passes, the Pitch LED turns on and dashes appear across
the pitch coupled display field of the FCC for a short period of time, the accelerometer reasonability
check monitor may have failed due to accelerometer offset. This condition should not occur once
the acceleration offset has been stored in the KCM 100 configuration module. The acceleration
offset is stored automatically by the software after the KC 140 has been operating in normal mode
for 10 minutes.
2.2.2.2 Low Voltage Monitor:
For --5302, --54XX, --55XX, --77XX, --7802 and --79XX versions or --5101 and --5201 units with
SW version 01/06: If the aircraft voltage goes below 10V, the AP will be disconnected and MET
will be disabled. Autopilot and MET operation will be allowed after the aircraft voltage goes above
10V. This monitor runs continuously whether the AP is engaged or not.
2.2.2.3 Baro Reference Monitor:
(--7xxx FCCs only) If the remote barometer input is <7.5% or >113% of the Baro Reference voltage
(nominally, <0.3V or >4.5 V), the monitor will fail and revert to using the baro select knob on the
KC 140. These values correspond to a valid range of 28.00 to 32.00 in Hg . If this monitor fails,
the selected altitude window will be dashed and altitude alerting and altitude arm mode will be
disabled.
2.2.2.4 Pressure Sensor Monitor:
If the pressure sensor output is < --2,500 ft or > +40,000 ft, the monitor will fail and disconnect all
pitch modes. Pitch Axis operation will be disallowed until the pressure sensor output is in a valid
range.
In --7xxx flavors, the selected altitude display will be dashed and altitude alerting will be disabled
during this condition.
2.2.2.5 Encoding Altimeter Monitor:
In --7xxx flavors, if the encoding altimeter code is invalid, the ALT ARM mode will be disconnected.
The selected altitude display will be dashed and altitude alerting will be disabled during this
condition.
Revision 2, Dec/2002
CS:15574F02.IDU
BENDIX/KING
KAP 140
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