February 6, 2014

Did You Know? SkyView's Wiring Redundancy

SkyView is designed that no one wire cut or unit failure should disable the system (if suitably equipped for redundancy).
One of the ways that SkyView offers failure tolerance is through the dual redundant data busses in the SkyView Network cables that are used to connect SkyView modules. The system constantly monitors both data buses for integrity. If a failure occurs on one of the two data busses, all SkyView Network communications continue as the system automatically transitions over to its redundant second data bus. When this happens, the pilot is provided with an alert to let them know that although there has been no loss of apparent capability, SkyView is operating without its redundant network. Incidentally, this “degraded” mode of operation is equivalent to most other EFIS systems in their normal configuration.
SkyView Network also includes dual, redundant power buses similar to the data buses. Not all devices that make up a SkyView system are connected via SkyView Network though. This includes many third-party peripherals, as well as SkyView’s own transponder and ADS-B modules that use RS-232 serial connections. SkyView has unique redundancy here too. Unlike any other EFIS systems, the serial transmit AND receive wires are connected to all SkyView displays in an aircraft in parallel. This means that the failure of a particular SkyView display does not disable communication with a connected serial device that requires bi-directional communication. So instead of having to choose a single display to communicate to such device, ALL SkyView displays are capable of communicating with all devices. So again, this means that should a display fail, you’ll have no loss of capability. No other EFIS manufacturer has this capability. Additionally, other critical signalling between units, such as the Autopilot LEVEL button, Autopilot Servo Disconnect Switch, Audio Alert Outputs, are all connected in parallel so that a failure of a particular SkyView display does not disable that capability. Finally, every SkyView display supports the connection of an optional dedicated backup battery (SV-BAT-320). If aircraft bus power is lost, the SkyView backup battery maintains power to the SkyView display and any device powered via SkyView Network. This includes most critical instruments, such as your ADAHRS and EMS modules (which provide your primary flight instruments and engine instruments). In short, unlike any other sport aviation EFIS system, SkyView was designed from the ground up to an EFIS platform that actually has the redundancy you should demand from your avionics. Steve Stroh
Technical Specialist