SkyView System Installation Guide - Dynon Avionics

SV-XPNDR-26X Installation, Configuration, and TestingIf you are using the Mutual Suppression feature, simply connect all of the Mutual Suppressionwires from devices that use them together.Ident Switch Input (optional)SkyView has an IDENT button in its transponder menu that is normally used to ident whenrequested by ATC. However, the ident switch input allows the IDENT function to be selectedusing a remote switch. The input is active low, and will be asserted when the voltage to groundis pulled below approximately 4 Volts. Therefore, a momentary switch to ground should beinstalled on this output if a remote ident switch is desired.Squat Switch Input (optional)The Squat switch input allows the transponder to automatically switch between Airborne andGround modes, and affects both the Mode S reply behavior and the ADS-B reporting behavior.The input will be asserted when the voltage to ground is pulled below approximately 4 Volts.The logical sense of the input can be programmed to be either active low or active high in theSkyView Setup Menu.This must be a mechanical switch that accurately reflects the aircraft’s on-ground status. Mode-S certification requirements state that this cannot be a simple airspeed switch.On an aircraft with no appropriate squat switch circuit this input should be left unconnected,and the transponder programmed to either ignore the input or use its “automatic”airborne/ground capability. See the AUTO ALT/GND SWITCH setting in the Transponder Settingssection of this chapter for further information about this capability.External Standby Input (optional)This input, when held low, places the transponder in Standby mode. It should be used to switchbetween transponders in an installation with two transponders. The input is active low, and willbe asserted when the voltage to ground is pulled below approximately 4 Volts.Direct Serial GPS Position InputAlthough SkyView can send its GPS information to the SV-XPNDR-26X for use with its ADS-Bposition-reporting capability, SkyView’s GPS does not meet any certification standard, and isnot TSO’d. Additionally, appropriately certified GPS units that can provide position forregulatory-compliant ADS-B installations may need to be connected directly to the ADS-B Outdevice (in this case, the SV-XPNDR-26X) for compliance credit. For these purposes, a dedicateddirect serial input is provided on the SV-XPNDR-26X module that allows an appropriate GPSreceiver serial output to be connected directly to the SV-XPNDR-26X.If you connect a GPS to this direct input, you must install a 1.21k resistor (included with the SV-XPNDR-26X) between the GPS and the SV-XPNDR-26X as shown in Figure 73.The SV-XPNDR-26X GPS input can recognise the following protocols: Industry standard “Aviation” protocol Freeflight GPS proprietary protocol11-10 SkyView System Installation Guide - Revision O