Sandel ST3400H HeliTAWS, Installation Manual

Page: 26 / 112

Discrete outputs are OPEN/GND and capable of sinking a maximum of 250milliamps to
ground when active. They can drive incandescent lamps and/or relays. Dimming of external
annunciators is accomplished by sourcing the annunciators from the helicopter day/night bus.
3.9.1 External Annunciator Functions
These switch/annunciator functions are on J2. The external switches perform the same
functions as their related front panel switches.
•
GS Inh
•
Mute Momentary press mutes an active Caution
•
Mute Press and hold invokes TAWS INH function
•
Sensitivity Momentary press toggles sensitivity selections.
•
Sensitivity Press and hold invokes OFF-APT mode
3.9.2 External Annunciator-Only Functions
These annunciator discrete outputs are available on J2:
•
Caution Alert
•
Warning Alert
•
Taws Inhibit
3.9.3 External Control Discrete Outputs
These control outputs are available:
•
Radalt Test
•
TCAS Inhibit
3.9.4 Annunciator Default Functions
ANNUNCIATORS
Marking Color Description
G/S INH YELLOW
Same function as on-screen G/S INH annunciation.
MUTE YELLOW Same function as on-screen MUTE annunciation.
SENS WHITE OR
CYAN
Alert sensitivity is LOW SENSE.
TAWS YELLOW Same as on-screen TAWS Yellow Caution.
TAWS RED Same as on-screen TAWS Red Warning.
TAWS INH YELLOW
TAWS INH function has been enabled or one or more
alerts have been disabled due to a fault.
CONTROL OUTPUTS
Signal Description
RADALT TEST
GND when the RA TEST pushbutton has been activated
TCAS INH GND when either CAUT or WARN are active. Used to mute the TCAS
audio.
82046-IM-K ST3400H INSTALLATION MANUAL Page 3-3