Garmin GPS 400W, Installation Manual

Page: 77 / 212

GNS 400W Series Installation Manual Page 4-23
190-00356-08 Rev. G
4.11.3 Discrete I/O
4.11.3.1 HTAWS
Pin Name Connector Pin I/O
HTAWS AUDIO ACTIVE P4001 44 Out
REDUCED PROTECTION (RP MODE) P4001 61 In
AURAL SUPPRESSION P4001 62 In
TERRAIN INHIBIT P4001 63 In
HTAWS AUDIO INHIBIT P4001 64 In
The HTAWS AUDIO ACTIVE output is active when the GNS 500W is playing an HTAWS alert. This
output can be connected to the Audio Inhibit input of other units with audio that is a lower priority than
HTAWS. This is an active low output capable of sinking 20mA.
The inputs are active low, by either a voltage to ground < 1.9V or the resistance to ground < 375 ohms.
The inputs are considered inactive if the voltage to ground is 11 to 33 VDC.
The REDUCED PROTECTION (RP MODE) input may be used to activate the HTAWS reduced
protection mode (RP MODE).
The AURAL SUPPRESSION input may be used to suppress HTAWS audio. Connect this input to a
momentary switch, which can be used to suppress the currently playing HTAWS caution aurals.
The TERRAIN INHIBIT input when toggled momentarily low, may be used to inhibit HTAWS alerts.
The HTAWS AUDIO INHIBIT input is used to inhibit HTAWS audio. This can be connected to inhibit
output lines of another unit whose audio is higher in priority.
4.11.4 HTAWS Configuration
Refer to Sections 5.3.27 and 5.3.28 for the HTAWS configuration.
4.11.5 HTAWS Calibration and Checkout
Refer to Section 5.4.9 and 0 for the HTAWS checkout.
4.11.6 HTAWS Annunciator Interconnect (optional)
Refer to Figure H-38 for external HTAWS annunciator interconnect.