Справочник Пользователя для Honeywell International Inc. KSN770
Draft
Page 3-43
6 Dec 2012
34-70-06
SYSTEM INSTALLATION MANUAL
066-01204 / 066-01213
© Honeywell International Inc. Do not copy without express permission of Honeywell.
3.9
Altitude/Airdata/Fuel Interface
3.9.1
Applicable Part Numbers
All part numbers and software revisions perform all Altitude/Airdata/Fuel functions.
3.9.2
Functions
A.
Altitude
All part numbers of the Bendix/King KEA 346-08 or above, with MOD 3 incorporated, are
compatible as a DC precision baro-corrected altitude or baro-setting source with the KSN 7xx
through the Analog BARO CORRECTION HI interface.
compatible as a DC precision baro-corrected altitude or baro-setting source with the KSN 7xx
through the Analog BARO CORRECTION HI interface.
All part numbers of the Bendix/King KEA 130A (not including KEA 130) are compatible as a baro
setting source with the KSN 7xx through the analog BARO CORRECTION HI interface.
setting source with the KSN 7xx through the analog BARO CORRECTION HI interface.
Kollsman-IDC model 519-28702-906 and Smiths model WL 1407/AM/MS 5 or 6 are compatible as
a baro setting source with the KSN 7xx through the Analog BARO CORRECTION HI interface.
a baro setting source with the KSN 7xx through the Analog BARO CORRECTION HI interface.
Kollsman-IDC models PD 44929-935, 28704-495, and 28704-XXX are compatible as a baro
setting source with the KSN 7xx through the Analog BARO CORRECTION HI interface.
setting source with the KSN 7xx through the Analog BARO CORRECTION HI interface.
The KSN 7xx is capable of receiving barometric altitude data from multiple sources. These include
(in order of priority):
(in order of priority):
• ARINC 429/419 digital air data computers (highest priority)
• RS-232 digital air data computers
• Gillham altitude data (lowest priority).
Certain altimeters provide an internal potentiometer that is driven by a baro setting mechanism.
The baro setting mechanism can be linear with inches of mercury (kPa) or linear with feet of baro
correction. Inches of mercury (kPa) represent the sea level baro metric pressure. The altitude
value in feet represents the difference between pressure altitude (gray code altitude) and the baro
corrected altitude. The potentiometer must be excited by an external voltage. If two or more
devices are monitoring this potentiometer output then only one of them can excite the
potentiometer and the other(s) must only monitor the reference input. In some aircraft installations
the KSN 7xx will be the only user of the baro setting potentiometer and it will need to supply the
excitation. In others, it will share the potentiometer with the flight control system. Some flight
control systems must always supply their own excitation. For these systems the KSN 7xx must not
supply the excitation but must monitor what the supplied excitation is so that it can divide its value
into the value from the potentiometer to determine the potentiometer value.
The baro setting mechanism can be linear with inches of mercury (kPa) or linear with feet of baro
correction. Inches of mercury (kPa) represent the sea level baro metric pressure. The altitude
value in feet represents the difference between pressure altitude (gray code altitude) and the baro
corrected altitude. The potentiometer must be excited by an external voltage. If two or more
devices are monitoring this potentiometer output then only one of them can excite the
potentiometer and the other(s) must only monitor the reference input. In some aircraft installations
the KSN 7xx will be the only user of the baro setting potentiometer and it will need to supply the
excitation. In others, it will share the potentiometer with the flight control system. Some flight
control systems must always supply their own excitation. For these systems the KSN 7xx must not
supply the excitation but must monitor what the supplied excitation is so that it can divide its value
into the value from the potentiometer to determine the potentiometer value.
The DC baro setting reference is configurable as input or output based on whether KSN 7xx is
going to provide the excitation voltage or monitor the externally supplied excitation voltage.
going to provide the excitation voltage or monitor the externally supplied excitation voltage.
Refer to the maintenance pages on how to set the parameters in the configuration module. There
are two major types of DC baro setting outputs on encoding altimeters: Baro set linear and altitude
correction linear.
are two major types of DC baro setting outputs on encoding altimeters: Baro set linear and altitude
correction linear.
Draft as of 10/15/2012