Transponder Operation
6-4
SkyView Pilot’s User Guide - Revision M
VFR
Press to quickly tune the VFR squawk code. This is usually 1200 in the US and 7000 in Europe.
Refer to the Installation Guide to set the VFR code that this button tunes. Once pressed, the
VFR button will remain highlighted until the transponder code is changed to show that you are
in VFR mode. Press the button while VFR is highlighted to return the transponder to the last
code tuned.
IDENT
Press to ident when requested to “ident” by ATC. “IDT” will be displayed in the Transponder
Status Area for the next 18 seconds as the transponder sends the ident signal. Note that if a
button is pressed to change the transponder mode or to turn it off, that action will be delayed
until the ident transmission completes.
Reported Pressure Altitude
At times it may be useful to know the altitude that is being reported to the transponder. Since
SkyView sends pressure altitude to the SV-XPNDR-26X, setting BARO to 29.92 will display the
pressure altitude being transmitted to the transponder in the normal SkyView altitude display
on the PFD page.
ADS-B OUT Transmissions
If SkyView has a valid GPS signal and a SV-XPNDR-26X module is installed and working, it
automatically provides ADS-B output at the appropriate integrity level for the GPS signal being
used.
ADS-B OUT transmissions that meet the 2020 FAA ADS-B equipment mandate require that a
TSO 146c GPS signal be directly provided from the GPS to a capable ADS-B device (such as the
SV-XPNDR-26X). For this purpose, a dedicated serial input is provided on the SV-XPNDR-26X
module that allows an appropriate GPS receiver serial output to be connected directly to the
SV-XPNDR-26X. As of this software version, the SV-XPNDR-26X is certified to TSO C166a. The
FAA has recently mandated TSO C166b for NextGen implementations, and a TSO-C166b
software upgrade for the transponder is planned. The current SV-XPNDR-26X is compatible
with Aviation format GPS outputs, used by Bendix/King, Garmin and others, as well as some
high-end GPS modules not likely to be used in a homebuilt or LSA aircraft. The popular Aviation
format output will not meet all the integrity requirements of the FAA NextGen system, and
therefore our TSO C166b software will include additional GPS interfaces as they become
available. This means that currently, the SV-XPNDR-26X’s ADS-B transmissions are not at a high
enough integrity level to meet the FAA’s 2020 ADS-B equipment mandate.
Refer to the installation guide for information on connecting a TSO 146c GPS directly to the SV-
XPNDR-26X for this compliance.