Technical data

Product Specification
HIF-2121/R5 CAGE CODE: 97896 SCALE: NONE SIZE: A DWG NO: 965-1176-601 REV: D
SHEET
103
6.9 System Outputs
Revision History
Effectivity
Date - Modified By Description of the Updates App. Cfg.
29-NOV-99 Peter Bateman Initial release and entry into PVCS -001 -001
24-MAY-00 Susie Wright SCR 4738: Add lamp format 2. General document cleanup. -003 -003
06-JUN-00 – Susie Wright Document only change – Deleted proprietary note from footer. -003 -003
01-DEC-00 – Susie Wright General document cleanup. -006 -006
27-FEB-01 – M. Calhoun SCR 5803: Added 6.9.3.7 for Steep Approach Lamp. -008 -008
11-JUN-01 – P. Bateman SCR 5794: Updated section 6.9.3 for addition of Flashing lamps. -008 -008
02-JUL-01 – S. Wright Added review comments -008 -008
This section describes the various outputs available with the EGPWS. Refer to the table in section 1.2.5.1 for a summary of
I/O capability.
6.9.1 Serial Output
The EGPWC provides two ARINC 429 output channels. Refer to the Installation Design Guide for a list of each of the
specific ARINC 429 output labels provided. These outputs consist of internal parameters that can be used for test purposes,
and discrete outputs that can be used both for test, driving EFIS displays, and recording. During EGPWS self test the SSM of
each output label is set to the functional test status code. The output types can be summarized as follows.
1) Internal data: Some internal data is output for test purposes only such as radio altitude used, computed true airspeed, etc.
2) Alert status: Each type of voice and lamp activity is mapped to a specific label/bit. This can be used to provide inputs to
EFIS (MKVIII EGPWS) and flight recorders.
3) Internal Mode status: Various internal EGPWC mode logic is transmitted for test purposes.
4) Fault diagnostic words are provided.
Also two channels of ARINC 453 data are provided to drive terrain displays for installations that use the Terrain Awareness
display function.
6.9.2 Audio Output
Mode computation outputs generally result in an audio voice message unless inputs are invalid or one of the audio
suppression discretes is active. The actual output message, or intended message during audio suppression, is sent to the alert
lamp logic for proper output activation.
The audio outputs consist of an 8-ohm amplifier to drive a flight deck speaker and a transformer isolated 600-ohm output to
drive audio interphone systems. The output volume is selectable as a configuration item (refer to the Installtion Design Guide)
which reduces the volume in steps of 6dB from the maximum (default) value. In addition a discrete can be used to reduce the
volume by a fixed 6dB for altitude callouts.
Two sets of voice messages are defined. Each set is selected by audio menu configuration. Refer to the Installtion Design
Guide for specific audio menu set definitions.
Table 6.9-1 is a list of the messages that can be selected for various alert conditions. The lamp column shows which lamp
output that an alert activates.
The audio inhibit discrete logic controls the audio outputs as follows. If selected then all voices are inhibited . An audio on
output discrete is set whenever an EGPWS audio message is active. This output is used to inhibit other audio systems.