EFIS Tones and "Voices"

[sbateman7799]

I just added a PAR200B Audio Panel (and the remote TRIG radio as Com1) to an older RV-12.
I made the various harnesses using the PAR200B diagrams and almost everything is working...except...I'm not hearing the various "voices" and tones from the Skyview Classic.
The stall sound is working.
Worked with the old set up (Garmin SL40 and Flightcom 403), so I suspect that I missed an audio input to the PAR200.

Looking at the wiring diagram, the various tones get mixed inside the AV-50000A control module.
I assumed that everything got mixed together and routed to the Intercom connector (in the AV-50000A) as "Mono Mixer Out, on pin 24...

So, two questions:
1. On what signals do the EFIS sounds get sent to the Intercom connector? Perhaps Stereo Mixer L/R Out?
2. What else, as well as the stall horn, get mixed onto Mono Mixer Out?

Thanks for any insight.
Steve.

 

[AZSteve053]

Good Morning,
Very difficult to effectively assist you without actual wiring diagram(s) of your new configuration - However:
EFIS outputs (voices & warnings) should be connected to one of the 4 unswitched inputs to audio panel (see IM) and #3 unswitched has an adjustable gain control from 50% to 200%.
EFIS outputs (voices & warnings) are TYPICALLY MONO, which is why unswitched inputs to audio panel are mono. Also note that the unswitched inputs are also differential (not referenced to ground) so be sure to wire them as such.
Hope this helps.

 

[sbateman7799]

Thanks for your reply.
I'm using unswitched input #1 on the intercom for what I think is the tone output from the AV-50000A control module (Mono Mixer Out).
The PAR IM states that the music inputs are differential, but I don't read anything about the unswitched inputs also being differential.
The unswitched inputs have a Hi and Lo signal, but if they were differential, I think I'd also see a reference, as with the music inputs
The signal "Mono Mixer Out" from the AV-50000 control module appears to be single-ended, not differential, so I connected it to unswitched input #1 Hi, and referenced it to ground (that is, unswitched input #1 Lo connected to ground).

I just re-read page 20-4 (section 2.4.3) of the PAR200B IM...it basically states that some avionics do not provide a separate audio low signal...so connect Lo to ground, which is what I did....I'm now wondering if there is a specific and separate audio ground...rather than the aircraft ground...I'll dig a bit deeper, tonight.

Thanks again.
SteveB.

 

[AZSteve053]

I attached a couple doc's I have that MAY be pertinent or at least help us communicate.
You say you connected AV-50000A "Mono Mixer Out", on pin 24 to PAR200B pin J1-31, and PAR200B pin J1-32 to ground on AV-50000A - is that correct ?
as per RV-12V Control board document page 6 of 10 GTR200 Interface ?? I'm UNSURE what this signal consist of internal to AV50000A.

I look at Rotax 912iS Skyview Electrical System - WH-00133-1 document page 2 of 11 which show PFD & MFD EFIS output audio R & L going to COM RADIO which then appears to go to page 4 of 11 GTR 200B Aux 2 IN Hi (9) & Lo (28) pins which shows L & R tied together going into GTR 200B pins. It appears to me this is the signal source you need to connect to unswitched Input #1 on the PAR200B.
I could be wrong - but this is the limited documentation I have on the RV12 & AV50000A...

Appears Stall warning from AV50000A comes out as a separate signal that went to the GTR 200B Aux 1 input

Possibly you'll need to use Aux 1 unswitched input for Stall & other MONO "warnings" from AV50000A AND Aux 2 unswitched input for EFIS Audio inputs.

BTW the unswitched inputs to the PAR200B have a Hi & Lo input pair each (thus differential) - the Lo MAY be connected internal to the PAR200B to ground or it may be a true differential. My brief reading of the IM lead me to believe it was true differential.

Over to you.

 

[SMRacer]

I just added a PAR200B Audio Panel (and the remote TRIG radio as Com1) to an older RV-12.
I made the various harnesses using the PAR200B diagrams and almost everything is working...except...I'm not hearing the various "voices" and tones from the Skyview Classic.
The stall sound is working.
Worked with the old set up (Garmin SL40 and Flightcom 403), so I suspect that I missed an audio input to the PAR200.

Looking at the wiring diagram, the various tones get mixed inside the AV-50000A control module.
I assumed that everything got mixed together and routed to the Intercom connector (in the AV-50000A) as "Mono Mixer Out, on pin 24...

So, two questions:
1. On what signals do the EFIS sounds get sent to the Intercom connector? Perhaps Stereo Mixer L/R Out?
2. What else, as well as the stall horn, get mixed onto Mono Mixer Out?

Thanks for any insight.
Steve.

I am chasing the (almost) exact same problem ever since I installed a PAR200B. I have an AFS system. If I learn anything from AFS tech support I will pass it on.

 

[sbateman7799]

After digging into the RV-12 wiring diagrams (two versions, using different intercom/radio combos), it appears that the EFIS sounds are called Stereo Mixer Out L and R. These are on pins 8 and 9 of the AV-50000A control modules Intercom header.
I verified this by "wiring" an old headset to these pins (shorted together for mono) and referenced to aircraft ground. Yep - there are the tones!
So, I removed the new harness and wired-in these (shorted) signals to Unswitched Input #2 Hi on the PAR 200B, J1 connector, pin 44.
Still didn't hear the tones...but more digging revealed that I connected Unswitched Input #2 Lo (pin 43) to a signal called Audio Ground, rather than aircraft ground...silly.

I'll rewire it on Friday to a/c ground and report back!
BTW: The Unswitched Inputs on the PAR200B are definitely single ended...I just needed to use the correct GND reference.
The Music Inputs #1 and #2 are indeed true differential signals and are referenced to the Audio Ground rather than aircraft ground.

 

[sbateman7799]

So...I'm still chasing this issue. I triple checked my harness design and re-re-re-studied the various RV-12 wiring diagrams.
My 12 used the "prior" diagram (Flight Com 403 and Garmin SL-40 radio), but I also referred to the "after" diagram which shows the hook-up of a Garmin GTR200 acting as intercom and COM1...a bit closer to my new set-up.

There are two tone outputs from the AV50000A control module (actually, from Logic-PCB Header 3, inside the AV50000).

MonoMixerOut, which is the stall tone. The stall switch provides a ground to Logic-PCB Header 3, inside the AV50000. Presumably, there is internal oscillator that provides the stall tone on MonoMixerOut. I wired this to Unswitched input 1 on the audio panel.

According to PS. Eng. Tech, Mark, the unswitched inputs "Lo" are internally connected to aircraft ground, so no need to actually connect ground wires to the Lo inputs.

The EFIS tones emerge on the signals StereoMixerOut L and R.
According to the Skyview installation manual, if the audio panel is mono (which the PAR200B unswitched input are), then L and R should be shorted together and wired to the Hi side of an unswitched input. All good and indeed that works...I hear the EFIS tones.

Now, when the stall switch is flipped, all I hear is a click and some fuzz...no tone.
I connected the unswitched 1 Lo to aircraft ground...no change.
I then connected unswitched 1 Lo to the signal called Audio Ground (pin 15 on the AV50000 Intercom header) - ah-ah...I heard the stall tone!
BUT...the EFIS tones were then silenced!

I swapped the unswitched input Hi signals to see if there might be an issue with one or the other inputs. Nope - same issue.

I have an email into Van's support to help me understand this. I'm beginning to think that there is something different with the output impedance and or output driver design for the two signals.

If I don't get to a solution, I'll stop messing around and this is what I will do:
1. I'll highjack the stall switch signal (which switches to ground) and feed it into a separate and isolated custom tone generator that I'll knock up on the bench and house in a grounded box.
2. I'll buffer that output, referenced to aircraft ground, and feed it into unswitched input 1 Hi.

I'd really like to hear from others who have tried to interface from a Van's AV50000 control moule or equivalent, to a PAR200B audio panel!

 

[sbateman7799]

So...I'm still chasing this issue. I triple checked my harness design and re-re-re-studied the various RV-12 wiring diagrams.
My 12 used the "prior" diagram (Flight Com 403 and Garmin SL-40 radio), but I also referred to the "after" diagram which shows the hook-up of a Garmin GTR200 acting as intercom and COM1...a bit closer to my new set-up.

There are two tone outputs from the AV50000A control module (actually, from Logic-PCB Header 3, inside the AV50000).

MonoMixerOut, which is the stall tone. The stall switch provides a ground to Logic-PCB Header 3, inside the AV50000. Presumably, there is internal oscillator that provides the stall tone on MonoMixerOut. I wired this to Unswitched input 1 on the audio panel.

According to PS. Eng. Tech, Mark, the unswitched inputs "Lo" are internally connected to aircraft ground, so no need to actually connect ground wires to the Lo inputs.

The EFIS tones emerge on the signals StereoMixerOut L and R.
According to the Skyview installation manual, if the audio panel is mono (which the PAR200B unswitched input are), then L and R should be shorted together and wired to the Hi side of an unswitched input. All good and indeed that works...I hear the EFIS tones.

Now, when the stall switch is flipped, all I hear is a click and some fuzz...no tone.
I connected the unswitched 1 Lo to aircraft ground...no change.
I then connected unswitched 1 Lo to the signal called Audio Ground (pin 15 on the AV50000 Intercom header) - ah-ah...I heard the stall tone!
BUT...the EFIS tones were then silenced!

I swapped the unswitched input Hi signals to see if there might be an issue with one or the other inputs. Nope - same issue.

I have an email into Van's support to help me understand this. I'm beginning to think that there is something different with the output impedance and or output driver design for the two signals.

If I don't get to a solution, I'll stop messing around and this is what I will do:
1. I'll highjack the stall switch signal (which switches to ground) and feed it into a separate and isolated custom tone generator that I'll knock up on the bench and house in a grounded box.
2. I'll buffer that output, referenced to aircraft ground, and feed it into unswitched input 1 Hi.

I'd really like to hear from others who have tried to interface from a Van's AV50000 control moule or equivalent, to a PAR200B audio panel!

Likely to be my last post in this thread.
I did make up a tone generator in case I needed to replace the stall tone circuit that comes from the AV50000A control module...but had an idea for another solution.
I took the EFIS L and R signals directly from the Skyview D37 connector (Pins 13 and 31), connected them together for mono as per the Skyview Installation Manual, and wired them directly (not through the AV50000) to the PAR200 Unswitchedinput#2 Hi. The stall circuit was left with MonoMixerOut connected to Unswitchedinput#1 Hi, and Audio Ground to Unswitchedinput#1 Lo.
Worked as it should.
So, I will change the harness accordingly and call it done.

As far as root cause...I can only conclude that there is a fault within the Logic-PCB Header3 in the AV50000A, but it has proven impossible to get a circuit diagram for that...and a direct email to Kevin at Van's has been met with deafening radio silence...oh, well...on to the next project.
If anyone wants more info on this and the debugging, please feel to call me (Steve): 4022008930