Audible Check Gear Alert

czfish

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Apr 10, 2017
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Equipment: HDX with SV-EMS

- I've got microswitch on Gear that signals when gear is all the way down. It's wired through SV-EMS as a Contact named GEAR
- I've put the "red/green light" widget in my engine display and it responds appropriately turning green when the gear is all the way down and red when it's not all the way down.
- I've setup the Gear Check speed in the Aircraft Information screen of the HDX at 95 knots, and enabled the VOICE for Gear Check in the SV SETUP.
- I'm getting one audible message when the gear is pulled up and the light turns red (regardless of the indicated airspeed). This message is not "Check Gear" but something more generic about the contact (sorry, I can't remember the specific message but it wasn't Check Gear). I'm performing this check in the hangar with a leaf blower aimed at my pitot tube and headset on, to allow variable indicated airspeed above and below the "Check Gear" speed, but I've also flown it and not gotten the alert when on a slow descent with the gear up.

Question:
- Is there something else I need to be doing to get the audible Check Gear alert to actually be "Check Gear" and to be triggered only when I'm below the check gear speed and the gear is not all the way extended?

Thanks very much,

Scott
 

Dynon

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Have you set the landing gear type in the aircraft information setup menu.

There's a section in the manual, sarting on page 7-70, that runs down the settings that need to be set for this to work. I think you have most of them set right
 

czfish

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Apr 10, 2017
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Yes, I'm following the section closely starting on page 7-70. The only thing I can find that's ambiguous in the instructions is how the switch itself is set up electrically. I've used the norma EMS switch assumptions that when a switch is closed it grounds the output voltage. When OFF it exhibits the EMS pull up resistor voltage which is usually 1-5v. Because I have the switch action set at the full down position of the Gear, it's sending a grounded signal to the EMS when the gear is all the way down. The installation manual on 7-71 is more ambiguous as it states:
  • Install the GEAR contact that when the landing gear is up, the state of the contact is UP and when the landing gear is down, the state of the contact is DOWN.

Where UP and DOWN contact state are not defined in terms of voltages.

Can you help clarify what UP and DOWN mean in this sentence from an output voltage standpoint as read by the EMS pin is?

Thanks,

Scott
 

Dynon

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So the system can be configured either way. IE, higher or lower voltage can be UP or DOWN. Electrically, if the circuit is open you should see 5V on the pin, and 0V when grounded.

Put another way: First, set up the pin in the Sensor input mapping setup page under setup. Then, back up a step, go to sensor setup, and then you change two of the range/state names to UP and DOWN, and choose your voltages (and visual colors and other settings) for each.
 

czfish

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Apr 10, 2017
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I really appreciate the help on this. I'm getting closer but not quite there yet. I've attached images of the engine panel and setup screens to reduce likelihood of confusion of what I actually have configured. At this point, in ground testing (0 KIAS) I'm getting an "Engine Monitor" instead of "Check Gear" audible warning when I raise the gear.

The Engine 50% display images just show that the HDX is recognizing that the Gear is UP and Down appropriately with the Red and green button light on the top right. You can see in the attached Engine Display screen that the text warning is "Gear Contact High".
IMG_8439.jpg
IMG_8440.jpg
IMG_8441.jpg
IMG_8444.jpg
IMG_8445.jpg
IMG_8446.jpg


The Setup screens show the EMS P11 is assigned as a CONTACT and labeled GEAR, and that the Voltage Ranges are set to correspond to UP>1V and Down <0.2 V, which seems to work fine (let me know if i should be using different transition voltages).

The last setup screen shows the Aircraft Information Page with the Check Gear speed set to 95kts and Gear Overspeed set to 110kts (the gear can take higher speeds, but I want the reminder early to pull the gear up).

If there's some other setup I need to do to change the audible warning from "Engine Monitor" to "Check Gear" let me know. When I pull the gear up at zero speed and get the audible warning, the text warning in the panel
 

czfish

I love flying!
Joined
Apr 10, 2017
Messages
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The system works with the settings shown last. It gives an "Engine Monitor" audible when I raise the gear before reaching the Check Gear Speed, and it gives "Check Gear" when the gear is not lowered all the way and I pass DOWN through the check gear speed.

Thanks for the help. It's good to have this behind me.
 
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