N104CD Avionics Interconnections

Bear with me as this page won't be completed until well after I'm flying...sometime in the next couple months.

I have the following equipment in my panel that requires some sort of signal integration:

Chelton 3-screen system
Crossbow 425EX AHRS
GNS480 Nav/Com
SL-30 Nav/Com
PS Engineering PMA8000 audio panel
Garmin GTX330 Transponder
Grand Rapids EIS 6000
TruTrak Digiflight II VSGV Autopilot
TruTrak ADI (currently Turn & Bank Installed)
WSI Weather
DAC ARINC 429 to Serial Converter
Mid-Continent MD200-306 CDI
ACK A30 mod 8 Encoder (2 serial 1 Gray Code outputs)

Most of this in some way or another is connected to one of the other items.  That's part of what makes planning for, and wiring a panel such a complicated task.  ** Note: It isn't necessarily all that complicated in all cases, but it's hard to gather all the required information sometimes.
Here I intend to eventually describe the entire interconnect layout, including pin number terminations, that were involve in my panel.

Chelton Interfaces
The Chelton screens have a few different harnesses.  The J1 harness is the main data interface harness to the outside world.  The J2 harness is a screen-to-screen interconnect harness, and the J3 harness is the main power, keyboard, and AHRS harness.

On my particular plane the J1 harness connects to: The J3 harness connects to:
Crossbow AHRS Interfaces
The crossbow only connects to the Chelton system, with one exception.  The TruTrak gets it's steering info via ARINC 429 signals, but gets it's GPS position info via serial.  So I have switchable options on my TruTrak so I can grab the serial data from J3 pin 1 on the Chelton and feed it to the TruTrak as a secondary GPS position source.

GNS480 Nav/Com #2
The GNS480 has many ARINC and Serial ports on it, but unfortunately, currently there are items in the panel that don't understand how to talk to it.  Theoretically, the GNS480 CDI display can be shown via serial interface, but Chelton needs to get it's engineers on it to get them to decode the communication so they can talk to it.  Therefore, the GNS480 is pretty simple in my installation.  The GNS480 talks to the MD200-306 CDI Head.  It also talks to my GTX330 via RS-232 using serial 1 on the GTX330 and Serial 6 on the GNS480.  The GNS480 is set to GTX33+TIS and the GTX330 is set to REMOTE and REMOTE+TIS.   The GNS480 is also receiving one of the ACK encoder RS-232 inputs for direct altitude input.  The ACK is running APOLLO 1200 Baud to do this, as the GNS480 uses the 17 Byte messaging that Apollo used.   The GNS480 could also be set to talk via serial to the SL-30, but my SL-30 serial lines are used for the Chelton already,
and it's not clear that it would add any real functionality.  The GNS480 will display the TIS from the GTX330, on screen.  One thing that would be nice to have but I don't, is if given the proper fuel/air data via serial, the GNS480 can display some of the fuel and range things on it's screen.  The chelton is more powerful though, so I'm satisfied without that on the 480.  The GNS480 of course also interfaces to the Audio Panel.  It has the standard headphone and Mic/Mic Key wires, but it also has a couple more.  The message audio out of the GNS480 goes to the audio panel, and then the PMA 8000 also ties back to the GNS480's Message Inhibit system.  I think this is supposed to mute the little GPS waypoint warnings and things, if other devices are currently sending audio alerts to the audio panel.  The GNS480 is also linked to my co-pilot stick switch so the co-pilot can flip-flop COM frequencies on the GNS480.

SL-30 Nav/Com #1
The SL-30 Nav/Com has very good integration with the Chelton.  It will output via serial the information needed to display the CDI needle on-screen.  The Chelton also will auto-tune the standby frequency to frequencies selected on the Chelton.  For instance, while choosing your destination airport on the chelton, you can also scroll through the list of frequencies at that airport (or ATC or ILS/NAV or any other frequency) and by hitting a button that frequency will occupy the standby frequency on your radio.  Then, a simple stick mounted flip-flip switch will send that frequency to active whenever you wish.  I have the SL-30 linked to the pilot's stick, since the SL-30 is my #1 Nav/Com and it's tied to my #1 navigational device...the Chelton.  The SL-30, while cheap, is a very powerful radio indeed.  Not only can it display on the Chelton screen the main NAV signal (Localizer or VOR), but it can also display what is in your standby NAV spot on the receiver.  It cal also monitor it's standby COM frequency, so in effect, I can monitor 2 frequencies on COM1, and 1 on COM2, all simultaneously.  Might be nice if youre flying the ADIZ, since then you can monitor 121.5 or AWOS/ATIS, flightwatch, and ATC, all at the same time.

PS Engineering PMA8000
This intercom was chosen for it's big list of functionality.  It interfaces to:
The PMA8000 has the ability to do "Split-Com" where the pilot can talk on COM1 and the Co-Pilot can talk on COM2, simultaneously.  That'll make my wife handy for calling flightwatch or grabbing the ATIS or making any necessary calls while I'm busy with ATC.  The Cellphone interface will be nice when on the ground, waiting to pick up a clearance before takeoff.  The music inputs I improvised on a bit.  I added a pair of jacks and pair of switches, so that either jack can feed either or both inputs.  Music #1 feeds the front seats, Music #2 feeds the back.  The beauty of it all is that if the kids are playing good music in the back, I can join in, but if they play the stuff that kids play, I can have my own. ;)  In the plane, I will be using one or two cool devices...a Creative Zen Vision personal Video/MP3/Photo player for myself, and an Iomega Screenplay personal Video/MP3/Photo player connected to 2 7" LCD's for the kids.   That should keep the whining down a bit...from me, I mean.  One additional feature I hooked up, that's pretty cool, is that if you don't have an AUX device, you can wire your AUX button to turn on "Karoke" mode.  That's where the radio noise doesn't continuously mute the music.  It's annoying when you're droning along, VFR at 8000', monitoring the radio to have some stinkin' Unicom frequency with a pilot 80 miles away doing touch-N-goes muting your music.  One minute you're singing along like you're alone in the shower, the next all you hear is Unicom.  This should be cool for some of those longer trips.  The kids also hate it when it mutes their music or video.  One other feature, which I almost didn't mention, but is probably the single most important feature of an audio panel if you have kids, is the "pilot isolate" and "crew isolate" function.  By the touch of a button, your screaming 3 year old can disappear from your intercom while you're 100' from minimums on that ILS, in the turbulence.  It was a complete life-saver for me in the past.

GTX330 Transponder
As mentioned above, the GTX 330 is tied to both the Chelton (through the ARINC to Serial converter) using ARINC #1, and it's tied to the GNS480 using Serial #1.  Both are programmed to provide TIS by using REMOTE+TIS, or GARMIN+TIS as appropriate.  When it receives it's altitude from the ACK A30 mod 8 encoder, it's receiving it with the ACK set to GARMIN/TRIMBLE 9600 baud, and the GTX330 is set to ICARUS ALT.  The GTX 330 does have both gray code and serial in, so you can hook up the ACK either way.  There is a trade off.  If you use serial, it's just 1 wire, BUT, the GTX 330 can't pass that same altitude out it's outbound serial interface...hence ONE of the reasons I have a separate serial altitude running to my GNS480.  The other reason is for redundancy.  Either device can be shut off without affecting the other.
If you use gray code, then it will work to pass it through serial out, but, if you buy an ACK A30.8, then why bother using gray code.  If I ever need serial altitude, I can always wire in gray code to the GTX330 later, and use the serial out for the new device.

Grand Rapids EIS 6000
The EIS 6000 is a powerful engine monitoring and air data system that interfaces with the Chelton.  Also available now to do this task is the
EIS from Advanced Control Systems.  Theirs is much prettier and supposedly will do the same job.  Either way, you'll get a good EIS that integrates with the Chelton screens.  You get things like Manifold Pressure, Tachometer, Airspeed, Altitude, OAT, CHT, EGT, Oil Temp, Oil Pressure, Fuel Pressure, AMPS (Optional), Fuel Level, Fuel Flow, and maybe even more.  The EIS 6000 unit that you get with the Chelton is running special software and comes with all the required probes.  I did one modification to the system and sent it in for a hardware and software upgrade that gives it 2 more AUX inputs, one of which I purchased a Hall-Effect sensor to do AMP monitoring.  At the same time, I purchased their commercial grade stainless steel fuel pressure sensor that was recommended.  The EIS 6000 is a VERY simple integration.  I have the Audio line running to an unswitched input in the audio panel, and I have the serial output line running to the J1 harness on the Chelton.  One wire to each unit, if I remember correctly.

TruTrak Digiflight II VSGV
This TruTrak autopilot is a VERY nice compromise and a good cash saver if you get the Chelton system.  When pricing out your panel, there are opportunities when you can actually remove some cost by spending more on your EFIS, and the autopilot is one of them.  When you combine the TruTrak with the Chelton, you get full vertical and horizontal autopilot control driven by the Chelton.  All it requires is a GPS position signal in so that it knows it's current direction of flight and rate of speed and position, and then the ARINC signalling to drive it.  It's only 3 wires in....2 ARINC and 1 Serial.  In my panel, I have the ARINC lines on a panel mounted switch that allows you to choose between the GNS480 and the Chelton to be the controlling unit.  There is another behind the panel switch that I've added as well, to switch the serial input.  The reason that this isn't combined with the other switch has it's own theory....and it all depends on who you talk to.  To me, the GNS480 is hands-down the most capable GPS, and I'd consider it the most reliable.  So my primary mode of operation will be to just use the GNS480 for the position info.  One of the TruTrak guys said this would be his choice.  Interestingly, TruTrak didn't wire their own RV-10 that way though.  They switched the RS-232 line to switch between the GNS480 and Chelton along with the ARINC lines.  Nothing wrong with that either,
as you probably wouldn't be allowing your Chelton to run your autopilot if you didn't trust it.  But, I figure as long as I have 2 sources,
I may as well use them.  I may wire it differently at a later time, depending on how it all flies.  The TruTrak will maintain it's direction without the GPS signal, but it will hunt a lot more and not be nearly as stable without the input.  With the behind the panel switch, I should be able to run with the GNS480 serial and the Chelton ARINC in "normal" mode, and then if I go to a reduced power mode and turn off my GNS480, I'll have to manually switch the line to the Chelton.  Like I said though, I may wire it differently at a later time.
Back to the autopilot choice though, the only autopilot that you could get that would do more than this one, in my panel, is the TruTrak Sorcerer.  What that gives you is the ability to not only control the autopilot using ARINC lines, but also the analog signals from the GNS480 to fly the vertical guided portions of the approach.  In my current config, I can fly the WAAS glideslope with the Chelton and monitor it with the GNS480, but if my Chelton dies and I'm flying by GNS480 alone, I'm going to have to hand-fly the vertical slope.  Since I'm doubtful the Chelton will be out of service often, I look at the advantage that I saved over $4000 on my autopilot by getting the VSGV.

TruTrak ADI
Presently the ADI is one of the items that I know the least about from a wiring perspective.  TruTrak has been slow to get this out (in 2.25"), so I'm temporarily using a TruTrak Turn-N-Bank.  The TNB only gets power, and nothing else.  The ADI will also get the same RS-232 GPS position signal as described above with the autopilot.

WSI Weather
I'm not sure that the WSI unit can't interface with the GNS480, but in my panel, the WSI is interfaced only the the Chelton.  It communicates by only an RS-232 pair and is very easy to wire.  You have to turn Flow Control off on the WSI, and tell the Chelton that WSI is installed, but other than that it should just work.  I can't comment much on the operation yet, as I won't activate my subscription until I start flying.

DAC ARINC 429 to Serial (RS-232) Converter
The purpose of the ARINC converter is solely to allow the GTX 330 to transmit TIS data to the Chelton.  The Chelton doesn't have too many ARINC inputs, so it needs the data via serial.  The GDC34A provides the Chelton with 2 additional ARINC inputs and 1 additional ARINC output for expansion.  It's a pretty simple box to wire, requiring ARINC In from the GTX330 (Using Channel 1), and RS-232 to the Chelton J1 harness.  The ARINC out can be used to send things like heading data to your 430/480/530 for wind correction, or other uses, and the additional ARINC input can be used to display things like the CDI from the 430/480/530 on the Chelton screen.  I can't remember if the GTX330 needs to be set to Low speed ARINC for the connection, but I thought I had heard this long ago, and it gets channel 1 configured for Garming+TIS. The ARINC speed setting on the Chelton side is "HI" for both DAC ports.  If Low doesn't work on the GTX330, try HIGH there.  It's been a while and I don't remember my GTX330 settings.  The 2 ARINC inputs on the DAC GDC34A are individually configurable except for speed, so the speeds will be set the same, but you can provide the input from the GTX330 on either DAC input, and the same with the GSN430/480/530.  In software version 6.0A13 or greater on the Chelton, you have the opportunity to configure data types individually for either ARINC ipnut.

Fuse 1A Connects To:
Pin 1 +12V
Pin 2 Serial Out (TX) Chelton: J1 Pin 5 (RX)
Pin 3 Serial In (RX) Chelton: J1 Pin 47 (TX)
Pin 11 Serial Grounds (Shields) Chelton: J1 Pin 26 (GND)
Pin 5 ARINC 429 RX 1A GTX 330: Pin 37 ARINC 429 Out 1A
Pin 6 ARINC 429 RX 1B GTX 330: Pin 34 ARINC 429 Out 1B
Pin 7 ARINC 429 TX A Connect to ARINC source such as GNS430/480
Pin 8 ARINC 429 TX B Connect to ARINC destination like GNS430/480
Pin 9 GND - Power GND
Pin 10 Chassis Ground
Pin 13 Common - RX Shield
Pin 14 ARINC 429 RX 2A Connect to ARINC source such as GNS430/480
Pin 15 ARINC 429 RX 2B Connect to ARINC source such as GNS430/480

Mid Continent MD200-306
The MD200-306 is an improved model of the standard CDI.  I have it only interfaced to my GNS480, as my Chelton will display the SL-30's
needle on it.  The MD200-306 features the ability to fly back-courses which I believe means you just don't have to remember to fly the needles backwards.  It may be that it only annunciates that it's a back course approach.  I'll have to find that out when I fly it for some practice, but anyway, it's got that additional feature beyond the standard Garmin CDI.

Ack A30 Mod 8 Altitude Encoder
As described above, the Ack encoder is a pretty powerful little box, and it's easy to wire.  It has 2 serial and 1 Gray Code output, and the serials are jumper configured to run in different formats and baud rates.  Default is 1200 baud Apollo Format, which works with my GNS480.  The GTX330 requires GARMIN/TRIMBLE 9600 baud format, which is easily set with jumpers.  I'm not currently using Gray Code, but it does come with all the harnesses you need to do all of this stuff.  I'm only using a couple of pins.  2 for power, and one serial output wire to both my GNS480 and GTX330.  I think those are pins 7 and 14.  The serial in to the GNS480 is Serial 8RX.  The serial in to the GTX330 is Serial 2, and it only needs to be configured on the input side and gets set to ICARUS ALT.


I'll try to add more info to this page after I get flying and have more time.  I'll add charts with pin connections and anything else I can.