Greg Arehart

Greg Arehart

Well Known Member
Just got myself a Garmin 495 which I want to connect to my SL30. GPS495 manual says to "connect the data out pin on the 495 (blue wire) to the RxD pin on the SL-30." According to my SL-30 installation manual, there IS NO RxD pin on the Comm side of the radio. There IS an RxD pin (#4) on the Nav side, but that is already wired into my Dynon D-100. What do I do? How do these interface?

Thanks,

greg
 
Greg Arehart said:
Just got myself a Garmin 495 which I want to connect to my SL30. GPS495 manual says to "connect the data out pin on the 495 (blue wire) to the RxD pin on the SL-30." According to my SL-30 installation manual, there IS NO RxD pin on the Comm side of the radio. There IS an RxD pin (#4) on the Nav side, but that is already wired into my Dynon D-100. What do I do? How do these interface?
Click to expand...

Greg,

I think you have the correct pin. A serial input can only receive data from one source, so you'll have to decide whether you want the radio to be connected to your GPS or your EFIS.

good luck,
mcb
 
Matt,

Thanks for the quick reply. That's what I suspected, but certainly not what Garmin provides in the instructions. So, perhaps the best situation might be to put a toggle with two inputs (one from the Dynon, the other from the 495) so I could swap between the two? Do you see any problems with that?

thanks,
greg
 
Greg Arehart said:
So, perhaps the best situation might be to put a toggle with two inputs (one from the Dynon, the other from the 495) so I could swap between the two? Do you see any problems with that?
Click to expand...

It seems like that would work, although if it was my airplane and I was faced with adding a separate toggle switch to enable this feature, I'd probably be content with reaching out my hand to tune the knobs on the radio instead. :)

good luck,
mcb
 
Not really sure what I'm trying to do other than have these things talk to each other. As I am now flying a 1961 C172, all this electronic stuff is new to me. My understanding (poor as it is) is that the radio frequencies can automatically be sent from the GPS database to the SL30. As you indicate Matt, I'm not sure that is worth the switch. My other understanding is that some of the GPS info can be sent to the Dynon (D100) to drive things like the HSI. This is much of the part I don't understand - Rivethead, is there a simple way to wire the 496 to send this kind of data to the Dynon? In the end, I'm not sure I NEED any of this, but as long as I have the equipment, why not try to get the most out of it.

Thanks for any advice.

greg
 
Hi Greg,

As far as I know the Dynon will not pass through the GPS freq data to the SL-30 like some other EFISes will....so, as Matt said the radio can't have 2 Rx's, so you're stuck with a switch or only using one item. Note, the frequencies to SL-30 are a marginally nifty feature, but hardly something I'd go out of my way to enable.

It's not really Garmin's fault, because the SL-30 is mainly meant to be wired up to run CDI's, etc.. or to attach to EFISes. The radio came first (not by them), the GPS came later. In normal installations without an EFIS running through the serial lines, a CDI or such runs through analog connections, leaving the serial line open for the GPS. It's our wonderful world of experimental EFISes having the ability to communicate with the radio via serial lines that is complicating your install.

Anyway, in the end you're stuck with a toggle or perhaps just not using the freq load. I don't find it to be a "must have" bit of functionality over a CDI myself....but that's just me. However, some EFISes (and perhaps someday Dynon-I just don't know) will pass the GPS freq data through the EFIS to the radio, eliminating that issues.

My 2 cents as usual!

Cheers,
Stein
 
So, it sounds like the simplest solution is just to wire up the GPS as a standalone unit and not try to get it to pass information anywhere. I already have the harness connecting the Dynon to the SL30. It's really not a big deal to twist the radio knobs to set a frequency. I had just been wondering about all this since the install manuals for the Garmin stuff are clearly not for the uninitiated amateur like me (but I sure like the Dynon manuals, which provide clear and simple info!).

Thanks

greg
 
Greg,

Is what you are trying to accomplish the following?:

1. Send the 495 GPS track data from the 495 to the Dynon, plus
2. Send the 495 freq (autoload) data from the 495 to the SL-40, plus
3. Send the SL-30 Nav (VOR/ILS) signal to the Dynon.

I have a D100/396/SL-40 set-up, and for 1. and 2., I split the blue wire out from the 396 and connected to pin 22 on the Dynon and the RxD pin (I believe, will check) on the SL-40. I do get track data on the D100 and Freq loading on the SL-40.

Seems the set up would be the same with the SL-30 for 1. and 2., and I'd think the SL-30 would have a separate pin to transmit VOR/ILS Nav data out (but that's where I could be wrong!). But if it did, that way you'd get all the features you want. Have you checked for a transmit pin, or is pin 4 either transmit or recieve (and you must choose one)? I looked on Garmin's website and couldn't find an install manual to research it...no joy there. I do know that you'd have to wire the SL-30 Nav signal and 495 Nav signal through a 3-way switch to the Dynon, or use an HS-34, to get both GPS and VOR/ILS to the Dynon (see page 3-5 on the D100 install manual).

I could be way off on this, so take it with a grain of salt. Maybe you have to choose between "data in" or "data out" to/from the SL-30. Stein and the other smart avionics guys would know best on that.

Good luck! Also, sent you a PM...got ya a spot in the hangar on Nov 1st! Gimme a call!

Cheers,
Bob

Cheers,
Bob
 
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Interesting

I have a similar setup but with the HS34, everything appears to be working but I am not flying yet to be sure.
I have the 496 TX line wired to a terminal block that fans out as follows:
1. HS34 Pin 1 (serial 1 RX) GPS input to HSI
2. SL30 Pin 4 (serial RX) Frequency upload to standby channel
3. ADI II Pin 17 (serial RX) GPS track to autopilot
4. SL30 Pin 5 (serial TX) goes to HS34 Pin 2 (serial 2 RX) SL30 NAV to HSI
This is to enable 496 frequency upload to SL30 standby channel, GPS input to D100 HSI, GPS track into the A/P and SL30 into the D100 HSI. . The HS34 switches the NAV inputs between the GPS and the SL30.
From all the manuals and everything else I have read this should work, have I missed something in this setup? From looking at the SL30 manual and the D100 manual I could not see what I would get from the D100 TX to SL30 RX connection and the 496 RX connection seems to only be of value if you have a GTX 330 transponder for TIS information (I have a GTX327)
 
GPS feed

Just run your GPS Tx line to a central terminal. Then feed from that terminal to every component that wants it from there. I'm currently feeding GTX 327 transponder, Dynon D180, SL 40 comm. Everything works perfectly.

Transponder goes to Alt or standby automaticly, load an approach from 496 and HSI course needle slews to inbound course, and by hitting recall on SL40 you can scroll through the frequencies for your destination loaded in 496.
 
Greg,

Sounds like Dave may have the ticket here. If you don't have an HS-34:

Split the 495's blue wire, and run one of the splits to pin 4 on the SL-30 (for freq loading), and the other split to a three-way switch (per Dynon's manual).

Run a wire from pin 5 on the SL-30 to the three-way switch.

Wire the output of the three-way switch to pin 22 on the Dynon (this gives you switchable GPS or VOR/ILS track to the Dynon).

Caveat from me...I'm no pro (don't want to be the blind leading the not-so blind!), but it sounds reasonable. Just to be sure, I'll ask WWSD (What Would Stein Do?) :)

I'll hold the fire extinguisher when you throw the switches! ;)

Edit: Just saw John's post, and didn't know that the 327 can take the GPS signal too (cool!). So that would mean 3 splits on the 495 data out line. Hey John, 3 quick Q's on the transponder feature: What pin on the 327 takes the GPS signal?; Do you know what signal or event causes the GPS to tell the 327 to go from STBY to ALT (and back)?; Do you know if the 396 has this transponder interface feature (like the 495/6). Thanks!

Cheers,
Bob
 
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Pin 19 on 327

It is pin 19 on the 327 (serial RX) and I think it looks for speed and alt cues to switch (speed > XXX alt increase >XXX).
I think I wired this also, plan to check today.
 
327

Bob
My 327 has rs232 ch1 on my Dynon for encoder, and rs232 ch2 recieves from the 396 or 496.
In the 327 setup menu rs232 input is set to Icarus Alt on ch1 and on ch2 its set to GPS.
Also if you're using a Dynon for Alt. encoding Set the Dynon "Alt enc" to format 4.

In the 327 setup menu you also must enable "auto standby", this feature works great for turning the transponder on, but only seems to turn it to standby about half the time.

Also remember to set your 396/496 in the setup menu output, to "Aviation and VHF".

Good luck
 
John,

Thanks much! I am using the Dynon as the encoder (format 4), and Icarus is set on the 327. Checked good with ATC the other day (including Mode C...once I pushed the ALT button! :eek:)

Aviation and VHF is in the 396 set-up (after much button-smashing and experimetation!) GPS signal to D100 looks OK (though my winds seemed 180 out yesterday...but that's another thread!)

Will see about splitting the blue wire from the 396 again, and attaching to the 327's pin 19 (thanks Dave), and then will play with the menus and try to set up the auto-standby feature.

Don'tcha love gadgets! :) Thanks again for the straight skinny!

Off to Greg's to see if we can figure his out!

Cheers,
Bob
 
Its pin 2 on the 327

Just checked my wiring on the plane today and the Dynon encoder TX goes to pin 19 on the 327 and the 496 goes to pin 2, this gives the GPS input for the auto ALT/STBY function.
I have PDF's of the manuals if you need a copy.
 
Roger that, pin 2

Thanks Dave! Would appreciate a copy of the .pdf's and thanks for the offer! I'll forward a copy to Greg too. My e-mail: [email protected]

Thanks again!

Cheers,
Bob
 
how many dynons

i have two dynons and the sl30 talks to one and the gps talks to the other. when the gps isnt on both dynons present the same info. i guess over the DSAB. when it is on one presents gps and one presents sl30 cdi. i dont bother with the freq. stuff.
 
cytoxin said:
i have two dynons and the sl30 talks to one and the gps talks to the other. when the gps isnt on both dynons present the same info. i guess over the DSAB. when it is on one presents gps and one presents sl30 cdi. i dont bother with the freq. stuff.
Click to expand...

William,

That's pretty neat! Didn't know two Dynons could do that when DSAB'd (as I read your post I was thinking they might conflict in some way...obviously not, and nice that you got it to work...lot's of options on info presentation that way!).

I'm guessing that you wired the SL-30 Serial Tx line to pin 22 on one Dynon, and the GPS (is it a Garmin?) data out wire to pin 22 on the other Dynon. Did you then tie the two Dynon pin 22's together?

Are there any settings in the HSI menu that you had to select to make it work that way?

Does it also work that if the SL-30 Nav freq is not tuned to a nearby station, that both display GPS track?

Just interested, as I only have an SL-40, but know others that have multiple Dynons and a -30, and may like the idea.

Cheers,
Bob
 
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