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VOR/LOC/GS setup for GTN to KI-525a

Im going over the setup of my GTN-650 and I an bit curious on what is the correct settings.

My GTN-650 feeds the KI-525a. Its working pretty good(to my standards).
However I would love to learn what is the most correct settings.

AIRINC 429: Tx Speed(low/high?), SDI (common or VOR/ILS1)

spirit49
LOIH

The KI-525 uses analog interconnects with the GTN-650.

ARINC 429 is a digital bus, which can be used to transmit and receive all kind of data. Most glass products will receive digital data from the GTN. It is used for the CDI for both NAV and GS for example, and the OBS back to the GTN. In this case, both must use the same speed.

In your case the ARINC 429 is not applicable (for the KI-525A)

JP-Avionics
EHMZ

OK
So it doesn’t matter what is in these fields then?!
Its kind of confusing because you calibrate the OBS resolver in the line above, and select DME Mode below. Both valid fro the KI-525a and my KN-63.

Thanks.

spirit49
LOIH

In your situation it is likely the ARINC 429 NAV output is not connected. If it would be connected, it for sure is not connected to the KI-5252A. Therefore the settings doesn’t matter for the KI-525 operation.

If everything went fine your Garmin dealer should have issued a document, stating which settings where used, and the motivation for these settings. They should also know what kind of equipment is interfaced and which settings are ok.

JP-Avionics
EHMZ

I don’t know the GTN650 but in say the Sandel SN3500 EHSI, which can emulate the KI525 for the purpose of driving an analog autopilot, the config involves specifying the HSI to be emulated by its name (from a pulldown menu of different HSI types) and that automatically sets up the right gain.

There is an additional parameter where you can tweak the output but normally that isn’t needed.

For driving different HSIs, the GTN650 must have a “gain” setting so the right full-scale voltage can be output for the lateral and vertical deviations.

Administrator
Shoreham EGKA, United Kingdom

Isn’t the full deflection voltage supposed to be standardized? So why do you need to adjust it?

Don’t know about the GTN, but my previous GPS only had a gain setting until they fixed the drive circuitry

LSZK, Switzerland

Peter, the settings you are indicated are completly different.

The GNC, GNS and GTN series can interface with:

- Analog indicators, such as the MD-200, GI-102, GI-106, KI-202, KI-206, KI-525A
- Converter Indicators (composite signals) suchs as the KI-203, KI-204, KI-208, KI-209
- Digital indicators (ARINC signals) such as Aspen EFD1000, Avidyne EX500 and EX5000

The Arinc setting of spirit49 is the NAV ARINC 429 output. This bus is used a two different speeds, hence the selection to select the correct speed. On SDI it will transmit a label from which unit the data is from. On common the SDI = 0, On VOR/ILS1, SDI = 1 (Pilot) and on VOR/ILS, SDI = 2 (Co-pilot).
The GNC, GNS or GTN will respond to data received for SDI 0 and for SDI 1 or 2 depending on settings. On all data transmitted onto the bus it is clear to all equipment from which equipment (pilot or copilot) the data is being received.

JP-Avionics
EHMZ

tomjnx is right. Altough often there is an adjustment for alignment purpuses when required. This is basically to match up for component error’s.
Peter is mistaking spirit49 settings with autopilot gain settings. On most systems you can set the autopilot gain setting. This is how the autopilot responds to an error signal. If the autopilot gets of track it must correct with a certain amount, this amount is set using these gain settings. To much gain and the autopilot will overshoot and cause oscillations / instability. Not enough gain and the autopilot will undershoot (it won’t make enough correction to stay on track).

JP-Avionics
EHMZ

Yes, the ARINC429 is not relevant to any HSI in GA use. They are all analog.

Administrator
Shoreham EGKA, United Kingdom

Well, that depends. If you have an PFD with HSI suchs as the Aspen EFD1000 Pro then you will use ARINC 429. On older products you will typically use analog signals.

JP-Avionics
EHMZ
14 Posts
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