I hear the theme music and the star wand sweeping the rainbow out with the catch phrase "the more you know". Ha ha. Good info. Thank you.
The salient Par in the 10.1 Horizon User Manual:
After power-up the AHRS will enter alignment and will provide attitude data once this process is complete. With minimal movement of the airplane attitude data is usually available by the time the EFIS completes booting. Continuous movement can extend the alignment time.
What I noticed is I had lots of questions when I got the unit and poured over the manual to no avail. I found or was tipped off the Hx manual had more detail and much of it applies. True. The Hx has detailed wiring diagram example but none in Horz 10.1 documents. They are close enough that the Hx is helpful. I don't think it is a burden to wait 40 seconds and push a button. EFIS and EIS should be on for start.
In fact as soon as you get butt in seat, turn on the avionics and by the time you are strapped in, have your headset on, way more than 40 seconds has elapsed. I am use to airplanes that are HOT not cold, the DC and AC buses are running before I even get on plane.
The manual for 10.1 Horz has an error:
5.2.4.6 Rebooting the Screen
In the unlikely event a of a serious software fault, the EFIS will automatically restart itself.
This process is very fast (a few seconds) and will return the EFIS to the page it was
previously on. It is unlikely you would ever encounter this.
In the even less likely event that the automatic recovery failed to detect the serious
software fault, causing the screen to stop responding, the EFIS can be rebooted using the
front panel softkeys. To force a re-boot, press and hold the outer left and outer right white
softkeys at the same time to reboot the display unit. Since this action does not affect the
AHRS, it will continue to provide attitude data without interruption, thus attitude data will
be available when the EFIS finishes re-booting. This re-booting process will take about 30
seconds
Then it shows the Hz display with a single row of 5 buttons along bottom. The 10.1 Horz
has 9 buttons on bottom and 6 on right side, plus the two knobs which also have push to
select function. I am guessing the fast boot function or quicker re-boot is the still bottom
row from L to R button 1 and 9....