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Selector Switch

Posted: Sun Oct 16, 2016 6:28 pm
by Bayou Bert
I have the HXr, GTN650 and Vision 385. I have finally gotten around to learning to use the
EFIS to control the A/P. But...found out from Jeff, I didn't have the selector switch. Could
not find any info in the Autopilot documents. I used Approach Fast Stack for my avionics.
I called Tim and he looked at my file and yep I need a switch to control from the EFIS.
New harness on the way with switch.
So what exactly is the switch switching? Really feel dumb, but can't find anything to read.
Right now, I can put flight plan in 650, put EFIS on 650, hit GPSS on 385 and the course lines show
up on the EFIS and the auto pilot flies the flight plan. So what is going to change with the switch?
If someone could help explain or point me to some documents, I would be very grateful.

Thanks
Bert

Re: Selector Switch

Posted: Mon Oct 17, 2016 4:48 am
by Bobturner
The switch shifts the serial and ARINC input lines to the autopilot between the GPS and the EFIS. Advantages of controlling the autopilot from the EFIS: Easier to use interface; ability to use the autopilot to track VORs, headings, and ILS approaches. Simple one button push to initiate a missed approach.
PS Suggest you look at HX documents. Software is basically the same. HX schematic wiring diagrams show the switch.

Re: Selector Switch

Posted: Mon Oct 17, 2016 9:00 am
by Bayou Bert
Thanks Bob, so if I understand, I can put a flight plan in the 650, make sure the HXr has 650 selected, switch on EFIS,
and then control auto pilot from the EFIS?
Will go look at HX documents.

Thanks
Bert

Auto Pilot Help

Posted: Sun Apr 09, 2017 4:25 pm
by Bayou Bert
More help needed on this old thread.
I now have the switch, thank to Approach Fast Stack, that toggles the 650 between the
auto pilot and the HXr. Questions:
1. Should I be in the ENAV or GNAV mode?
2. Do the autopilot setting in the HXr need to be increased from all being 100%?
Sequence of events would be great on getting to EFIS control of the AP.
I have just been using Direct To to navigate with the 650 straight to the AP.
To use the EFIS?
1. Activate point in 650 using Direct To
2. Put AP mode in GPSS SVS
3. EFIS mode to?
Lost from there, what step actually takes control of the AP?
Generally lost, any and all help super appreciated.

Bert

Re: Auto Pilot Help

Posted: Sun Apr 09, 2017 10:21 pm
by Bobturner
Bayou Bert wrote:More help needed on this old thread.
I now have the switch, thank to Approach Fast Stack, that toggles the 650 between the
auto pilot and the HXr. Questions:
1. Should I be in the ENAV or GNAV mode?
2. Do the autopilot setting in the HXr need to be increased from all being 100%?
Sequence of events would be great on getting to EFIS control of the AP.
I have just been using Direct To to navigate with the 650 straight to the AP.
To use the EFIS?
1. Activate point in 650 using Direct To
2. Put AP mode in GPSS SVS
3. EFIS mode to?
Lost from there, what step actually takes control of the AP?
Generally lost, any and all help super appreciated.

Bert
I use a Trio Pro so some answers may be different for you.
1. Use ENAV for VOR or LOC tracking. Use GNAV if using the GPS for navigating.
2. Different autopilot so our settings may be different.
The HX or HXr is constantly outputting the autopilot control data. Sequence for me: autopilot powered on, but servos disengaged. Set switch (GPS/EFIS) to EFIS. Select ENAV or GNAV as above. Engage servos. Done. (Trio auto-detects GPSS signals. You may have to do that manually with yours??).
Approaches take some more set up.

Re: Selector Switch

Posted: Mon Apr 10, 2017 4:41 pm
by Bobturner
I realize my last post was too short. What I really do is put my autopilot in 'heading' and 'altitude hold' mode first, just to make sure everything is working.
1. Set altitude on EFIS
2. Center heading bug
3. Set autopilot mode to heading in GRT menu.
4. Engage autopilot.
5. Set desired course on GPS (either 'direct' or thru flight plan for multiple legs) or VOR
6. Make sure EFIS nav source is set to GPS or VOR, as desired.
7. Go to autopilot menu on EFIS, select GNAV (if using GPS) or ENAV.

You should read the manual to try to understand the difference between GNAV and ENAV. GNAV passes the GPS commands thru to the autopilot. ENAV looks at the data and generates its own commands to the autopilot. GNAV does some things, like procedure turns and turn anticipation, that ENAV does not. OTOH, ENAV gives one button push transition to a missed approach, which GNAV does not. Read the manual for how to set up approaches. Use the 'arm' command in the menu.