G3X Discrete inputs

I am working on drawings for a G3X system and the manual is a bit vague on all of the possible configurations for the GEA 24 discrete inputs. I don't have the unit powered up yet so I can't play in the menus to look at the setups and I need to know if this configuration is possible before I install switches and run the wires.

I would like to have a gear down and locked and a gear up switch for each of the main and nose gear. I know I can configure two inputs for both down and up, but I don't know if I can configure for switches for main and nose down and up and also display status of both main and nose gear on the screen. Any G3X experts that can answer this? If not, I will need to series the main and nose switches together and just have an "all gear" up or down indication.

Brian Kraut
904-536-1780
[email protected]

To my knowledge, there isn't a way to tie multiple discrete inputs into a single action. So, as you stated, the only way I see it would be a set of switches in series which pull to ground when all gear are made, then you would have the action you want. Assign that discrete to the gear down function and the appropriate warnings would work. If it were me, I would have those switches separate from your gear light switches.

To keep it simple, I just ran a double pole double throw gear switch. One side operates the gear, the other pulls to ground when the gear is down. So, I will not get a warning if I only have 2 green vs 3, but I will get a warning if I forget them all together.. Worked on the last Lancair I built and the new Legacy will have the same system.

Hope that helps,
Tom

Really not looking for separate switches to be the same action. I want one set of switches to be nose gear and the second set to be main gear. What I don't know is if there are separate selections in the G3X for nose and main gear or if it is just one gear selection.

At some point I will wire up the panel and many of the modules on the bench and power it up and see what the setups are, but right now I am not to that point and am trying to run appropriate wires in the plane.

I think there are a coupe of things in play here. First you need a sufficient number of discretes available (6) in order to get three up locked / down locked lights. So go ahead and run wires for those. The problem is what other discretes are you willing to give up? You have to be careful when looking at the wiring diagrams in the install manual because General Purpose discretes can be shown multiple times and you might think you have more than you really do. I have maxed out my user defined discretes with a door discrete, speed brake, fuel pump on, sump quantity low.

Second, each user discrete can be designated as a particular type of discrete like; gear up, gear down, squat, door... If you set your discrete to one of those, then you get the special programmed function (like when the engine RPM is greater than XXXX and the door is unlocked or speed brake is down you get a warning).

If you need more discretes, you will have to install the GAD29 or GAP26 (I think) to get these features. I don't have one, but I think it has additional functions like the ones you seek.

Either way, you will need to wire 2 switches for each gear. You could also just install three bi-color LEDs in the panel and connect a group in series for up and the other for down, which could then be put into the GEA24 as a single discrete if you are just looking for a display message. You should probably think about two gear handle position discretes so that you know that what you commanded is actually the undercarriage configuration. The gear switches would be down stream of the handle switch.

brian257 said:

Really not looking for separate switches to be the same action. I want one set of switches to be nose gear and the second set to be main gear. What I don't know is if there are separate selections in the G3X for nose and main gear or if it is just one gear selection.

At some point I will wire up the panel and many of the modules on the bench and power it up and see what the setups are, but right now I am not to that point and am trying to run appropriate wires in the plane.

Click to expand...

discretes

Actually, with the GEA24 you can use some of the GP pins. You need to read the manual but the GP pins can be configured as a discrete Hi or Lo. You may need to add a resistor, so read the manual. I ended up using 4 unused GP pins for discrete functions.

If you need more, you can add a GAD27 which, among other things, gives you another 10(?) discrete inputs...

brian257 said:

I am working on drawings for a G3X system and the manual is a bit vague on all of the possible configurations for the GEA 24 discrete inputs. I don't have the unit powered up yet so I can't play in the menus to look at the setups and I need to know if this configuration is possible before I install switches and run the wires.

I would like to have a gear down and locked and a gear up switch for each of the main and nose gear. I know I can configure two inputs for both down and up, but I don't know if I can configure for switches for main and nose down and up and also display status of both main and nose gear on the screen. Any G3X experts that can answer this? If not, I will need to series the main and nose switches together and just have an "all gear" up or down indication.

Brian Kraut
904-536-1780
[email protected]

Click to expand...

Brian,

There is no provision to have separate gear warning systems for the main and landing gear. You would be able to implement a system to notify you of the status of your landing gear as a whole however. You would wire the discrete inputs in series to one discrete input to accomplish this.

Please feel free to reach out to us directly if you would like, at [email protected].

Thanks,

Justin