Eng/Du4 Message (Pfd); Dau 1-2 Miscmp-Msg Amber Message; Dau 1-2 Miscmp-Msg Blue Message - Honeywell SPZ-8000 Maintenance Manual

. The fault warning computer monitors for activity on the DU
wrap-around bus. The CHECK DU message is displayed as
appropriate for the DU'S
positional location (1 through 6)
in the aircraft.
The fault warning computer compares PFD format data against
actual sensor data. If the difference between the display
and the sensor exceed the appropriate threshold, for any one
parameter, the CHECK DU message is activated as appropriate
for the DU'S positional location in the aircraft.
2. F. (3) (d) ENG/DU4 Message (PFD) - These messages are active on the PFD
whenever the conditions for any one of the following criteria
are met:
. The fault warning computer monitors for act-ivity on the
DU
wrap-around bus.
The ENG and DU4 messages are displayed as
appropriate for the DU'S positional location in the
aircraft.
. The fault warning computer compares engine format data
against the actual sensor data. If the difference between
the display and sensor exceed the appropriate threshold, for
any one parameter, the ENG annunciation is activated. If
this condition exists with compacted EICAS format
(paragraph 2.H.) on DU4, the ENG message is displayed and
the DU4 message is suppressed.
(e) DAU 1-2 MISCMP-MSG Amber Message - The fault warning computer
compares the amber message activation logic between each
channel (A and B) of a particular DAU. If a difference is
detected between the DAU channels, the miscompare message is
activated as appropriate (i.e., DAU 1, 2, or 1-2).
(f) DAU 1-2 MISCMP-ENG Amber Message - The fault warning computer
compares primary engine data (EPR, TGT, LP, HP,
FF) between
channels A and B of each DAU. If the difference exceeds any
one of the following thresholds for 2 or more seconds, this
message will indicate the appropriate DAU: EPR - 0.5,
TGT - 200, LP - 20, HP - 20, FF - 1000.
(g) cWX VSPEEDS
Amber Message - When the AUTO VSPD mode is
active, the FWC compares the Vspeeds from FMS-PERF 1 and
FMS-PERF 2. If the Vspeeds differ by more than 3 knots or only
one performance computer is outputting valid Vspeeds, the
message is enabled.
(h) DAU 1-2 MISCMP-MSG Blue Message - The fault warning computer
compares the blue message activation logic between each channel
(A and B) of a particular DAU. If a difference is detected
between the DAU channels, the miscompare message is activated
as appropriate (i.e., DAU 1, 2, or 1-2).
22-14-00
Page 289
Aug 15/91
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