G1 and G2 Cirrus SR22 serial numbers 22-0435 to 22-1662 and SR20 from serial number 1337 until 1581 (basically all ‘non glovebox’ models with Avidyne PFD and MFD and the EMax engine monitoring option) are using the Avidyne engine instrumentation data acquisition computer „SIU". Also some of the earlier aircraft have been field upgraded. Later Avidyne Entegra / „non perspective“ serials (‚glovebox models‘) use the Avidyne „DAU" for the same purpose.
SIU and DAU are converting electrical and engine parameters to digital information, which is then displayed by the MFD (and - in DAU aircraft – by the PFD).
In SIU aircraft the primary engine instrumentation required for certification (RPM, manifold pressure, fuel flow, oil temperature and oil pressure) is provided by the classical analog instruments on the right side of the instrument panel. Similarly the essential bus voltage and, selectable, alternator 1, 2 or battery bus load (amps) are indicated by analog instruments. Main and essential bus voltage are also converted by the SIU and displayed by the MFD. Due to design constraints bus loads are converted but not displayed on the MFD. The latter constraints are also resolved as part of the EMAXplus™ installation.
In DAU aircraft the classical instrumentation has been eliminated and the PFD/MFD serve as primary displays to meet the respective certification requirements.
|System:||Micrcontroller based protocol converter, interface unit and aural alerter|
|Interfaces:||Dual RS232 ports, 5 digital inputs (0/28V), 1 digital input (push button switch) 2 digital outputs (28V LED lights), 1 Audio Output (500mV/500Ohm)|
|Voltage:||5 - 28V (max 40V)|
|Current:||40 mA (typical)|
|Environment:||-40°C..+85°C (industrial temperature range)|
|Humidity:||max. 80%, non condensing|
|Weight:||170g / 0.4lbs (processor unit)|
|Qualification:||DO-160D (applicable subset)
DO-178B DAL D
|Certification:||EASA Minor Change 10063938
(FAA acceptance per September 2017 bilateral Agreement between EASA and FAA - TIP Rev. 6)
Instructions for Continued Airworthiness,
Approved POH/FMS Supplement