SKY899
Installation Manual
Page 2-26 - Installation
009-11900-001
July 18, 2013
Revision F
2.11.1 Gilham Code (Encoding Altimeter)
These signals are Gilham code inputs coming from an airdata computer or altitude digitizer (encoding
altimeter). These 11 lines may be connected in parallel with the aircraft transponder. If the aircraft is
equipped with selectable altitude encoders, connect the altitude inputs so that SKY899 is always
connected to the selected encoder. (Reference ARINC 572-1.)
NOTE
If the aircraft has switched encoders that use 28V RETURN or
AIRCRAFT GROUND as reference for encoder selection, then
ALTITUDE COMMON should be left unconnected.
Altitude encoder connections:
A1 -to- P1-56
B1 -to- P1-59
C1 -to- P1-67
D2* -to- P1-70
A2 -to- P1-57
B2 -to- P1-60
C2 -to- P1-68
D4 -to- P1-71
A4 -to- P1-58
B4 -to- P1-61
C4 -to- P1-69
ALTITUDE COMMON - to P1-72
* If D2 is not used P1-70 should remain unconnected
2.11.2 ARINC-429 (ADC)
ARINC-429 (ADC) speed can be 12.5 or 100 kHz. Refer to paragraph 2.9.1 for ARINC-429 general
sensor input information.
2.12 (ARINC-429)
The GPS (ARINC-429) speed can be 12.5 or 100 kHz. Refer to paragraph 2.9.1 for ARINC-429 general
sensor input information. In order to use ADS-B, in the future when it is standardized, SKYWATCH HP
requires a GPS input that is GAMA or ARINC-743A compliant.
2.13 HEADING INPUT
Heading can be provided by synchro (XYZ) or ARINC-429 (attitude heading and reference system),
depending on the configuration settings. Heading source will be selected during system setup via the
service menu. Only one heading source, either compass Synchro or ARINC-429 should be connected.
NOTE
The SKY899 will work without heading input, but it will experience
degraded performance during high-rate-of-turn maneuvers. Therefore, it
is recommended that heading input be connected to the TRC. Heading
input will prevent intruders from dropping and reappearing on the
display while the aircraft is turning.
2.13.1 Compass Synchro (XYZ)
Synchro (XYZ) heading input accepts ARINC 407, 407-1 signals. The FLAG line input provides the TRC
with flag status (or heading valid) information. The status of the heading valid signal can be none, active
high, or active low (see appendix A for signal characteristics) and must be selected during system setup
via the service menu.
The document reference is online, please check the correspondence between the online documentation and the printed version.