GNS 400W Series Installation Manual Page 4-23190-00356-08 Rev. G4.11.3 Discrete I/O4.11.3.1 HTAWSPin Name Connector Pin I/OHTAWS AUDIO ACTIVE P4001 44 OutREDUCED PROTECTION (RP MODE) P4001 61 InAURAL SUPPRESSION P4001 62 InTERRAIN INHIBIT P4001 63 InHTAWS AUDIO INHIBIT P4001 64 InThe HTAWS AUDIO ACTIVE output is active when the GNS 500W is playing an HTAWS alert. Thisoutput can be connected to the Audio Inhibit input of other units with audio that is a lower priority thanHTAWS. 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 reducedprotection mode (RP MODE).The AURAL SUPPRESSION input may be used to suppress HTAWS audio. Connect this input to amomentary 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 inhibitoutput lines of another unit whose audio is higher in priority.4.11.4 HTAWS ConfigurationRefer to Sections 5.3.27 and 5.3.28 for the HTAWS configuration.4.11.5 HTAWS Calibration and CheckoutRefer 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.
