Need for Time and Date Input

[thibault]

I have completed installation of SV1000, SV700, single ADAHRS, EMS and pitch and roll servos into my Lancair Everything above is all Dynon. This equipment is integrated to a Garmin 430 through SV1000s Serial Port 1.

EMS sensors all work fine.

GPS data is arriving, so the map and SYNVIS work fine.

When I try to calibrate the compass, I can not due to no "time or date input". I already know that the Garmin 430 serial aviation data does not include date and time. The ARINC 429 data does include this.

Also, the installation guide implies that the autopilot servos require the compass calibration before they will test/calibrate. Is that true?

Am I missing something?

If this is all true, then is it also true that I need to add another GPS source that does provide time in the serial NMEA stream and use this at least until the ARINC 429 capability is availabe several months from now?

Is time used for anything important after compass calibration? If not, why isn't there a manual input method for supplying the time and date during compass calibration?

Needing to add a temporary, superfluous GPS (to get time) just for the next few months is very frustrating to consider.

 

[dynonsupport]

It doesn't disallow servo calibration if you don't calibrate the mag heading first, but heading mode issues are a possible artifact if the heading isn't well-calibrated.

As for the GPS issue, you will need a NMEA source to set the time until the ARINC converter arrives later this summer. Give us a call at 425-402-0433 and mention this thread - we have an idea that may work for you.

 

[thibault]

Made the call to support and the answer was not good.

You need a valid time/date input both to calibrate the compass and while flying later.

Have no choice but to add another GPS to my already finished installation (ordered a SV-GPS-250).

 

[n223rv]

Probably not a bad idea anyways.... Now you'll have a back up GPS...

 

[dynonsupport]

Originally we recommended that SkyView owners include the SV-GPS-250, but didn't require it.  We now realize we should change that into "VERY highly recommended."

The reasons are:
* We have found that the SV-GPS-250 is a better receiver (more sensitive) than most GPS receivers.
* It outputs NMEA GPS data at 5 Hz.  Many/most new GPS units have 5 Hz internally, but only output NMEA GPS data at 1 Hz.
* In case of airplane electrical failure, it uses the the SkyView back-up battery.  

-Robert
Dynon Marketing

 

[thibault]

Dynon,

Appreciate the candor about recommended equipment. If the literature had been more specific about the WHY of the recommendation, it would have saved grief.

I have now installed the GPS-250 and it works exactly as advertised. You are correct that it is very fast to first fix, even the very first time I powered it. Also the failover from Garmin 430 to GPS-250 and back seems to work just right. I set the GPS-250 to be Pos-2 and the 430 to be GPS-1. This makes the GPS-250 secondary to the 430 and primary when the 430 is absent, which is always, at power up, until the 430 finishes acquisition. This way the 250 updates the time during each start up.

Now I have three totally independant GPS receivers in the airplane (two are battery backed).

 

[dynonsupport]

The disadvantage to setting the GPS-250 to POS2 is that you will only get 1Hz updates when the 430 is working. We're really recommend using the GPS-250 as POS1 so you get the higher update rate from it.

 

[thibault]

OK. Guess I still don't understand. What I want to have happen is that all GPS info would come from my Garmin 430, Serial Input 1, whether for the map, HSI or whatever (except for the time, of course).

The following quote seems to imply that GPS-250, set as POS 1, would supersede the Garmin 430 for the map display. Also, the last paragraph below is still confusing. What does choose the source during operation mean?

SkyView System Installation Guide pg 4-13
Input Function Considerations and Priorities
Dynon’s Moving Map Page uses POS and GPS sources for its data. Regardless of the number of data sources in your system, this page prioritizes these sources and fails over to them as follows:
POS 1[ch61492] GPS 1[ch61492]GPS 2[ch61492]GPS 3[ch61492]GPS 4[ch61492]POS 2[ch61492]POS 3[ch61492]POS 4
For example, if your system has one SV-GPS-250 configured as POS 1 and a Garmin 396 configured as GPS 1, the Moving Map will always use the SV-GPS-250 as its primary data source. If the SV-GPS-250 fails or you configure its input function to NONE, the Moving Map Page will use the Garmin 396 (or other GPS source) configured as GPS 1 as its primary data source.

The SkyView HSI uses GPS and NAV sources for its overlays and the user must choose the source during operation.

 

[dynonsupport]

What we mean as "source" for moving map is the lat/long and altitude. That's all we use from your GPS. So the 430 sends us lat/long/alt at 1Hz, but the GPS-250 does it at 5Hz. The same position data is used for SynVis as well. We don't pull a database from your 430 to display on the map, so there is no advantage to the 430 being your primary, but there is a disadvantage to the slower data.

The other function of the 430 is to display an HSI. This is selected via the nav source button in the PFD menu. The whole reason we have "POS" sources is that they can't drive an HSI, since they have no navigation capabilities, so they don't show up on the HSI list. You can display any HSI source at any time, so you can display GPS 4 even if the current lat/long source is POS 1 or GPS 1.