SkyView - Dynon Avionics

SV-XPNDR-26X Installation, Configuration, and TestingMutual Suppression (optional)Mutual Suppression allows two or more transmitters on adjacent frequencies to inhibit theother transmitters when one is active to limit the interference effects. It is commonly usedbetween transponders and DME systems, and between transponders and collision avoidancesystems. Most installations will not make use of this feature, since most Dynon-equippedaircraft have only one transponder and often do not have DME equipment or other activetraffic system that interrogate other aircraft.The Mutual Suppression pin (18) is an ARINC compatible suppression bus interface, which actsas both an input and an output. The SV-XPNDR-26X will assert this signal when it is transmitting,and can be suppressed by other equipment that asserts the signal. The SV-XPNDR-26X willdrive approximately 24 Volts on the output (independently of supply voltage), and will treat theinput as active whenever the bus has greater than 10 Volts.If 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 behaviour 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 ignore the input.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.11-8 SkyView System Installation Guide - Revision J