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  #1  
Old 02-12-2015, 01:45 PM
Mike S's Avatar
Mike S Mike S is offline
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Location: Dayton Airpark, NV A34
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Default ADSB question

Here is a link to the NavWorx installation, presented as a block diagram.

http://www.navworx.com/PDFs/GRT-disp...ffic-block.pdf

Sorry, I cant figure out how to post the actual image

My question is the encoder input------it clearly shows the encoder going directly to the NavWorx box, and not to the transponder. Is this correct??

Should there also be an encoder feed to the transponder??

Should the encoder feed into/through the transponder to the NaxWorx unit?

If the encoder is already feeding the transponder, does the needed information back feed to the NavWorx unit over the RS 232 line??
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Mike Starkey
VAF 909

Rv-10, N210LM.

Flying as of 12/4/2010

Phase 1 done, 2/4/2011

Sold after 240+ wonderful hours of flight.

"Flying the airplane is more important than radioing your plight to a person on the ground incapable of understanding or doing anything about it."
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  #2  
Old 02-12-2015, 03:56 PM
BobTurner BobTurner is offline
 
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Location: Livermore, CA
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Default

Quote:
Originally Posted by Mike S View Post
Here is a link to the NavWorx installation, presented as a block diagram.

http://www.navworx.com/PDFs/GRT-disp...ffic-block.pdf

Sorry, I cant figure out how to post the actual image

My question is the encoder input------it clearly shows the encoder going directly to the NavWorx box, and not to the transponder. Is this correct??

Should there also be an encoder feed to the transponder??

Should the encoder feed into/through the transponder to the NaxWorx unit?

If the encoder is already feeding the transponder, does the needed information back feed to the NavWorx unit over the RS 232 line??
Q1. I do not think so. see Q2
Q2. yes, the transponder needs a pressure altitude feed. I believe the specs call for the ADSB and the transponder to use the same device for pressure altitude.
Q3 and Q4. I don't know, it depends on what the NavWorx can decode, formats and speed, etc., as well as what the transponder can send.

I do know that the GTX-327 can take in data (including pressure altitude) from the EFIS and send it back out (I forget the format). I use this to pass thru data from the HX to the 430W. Presumably that data includes the squawk code, as well as the pressure altitude, both of which the ADSB-out needs.
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  #3  
Old 02-12-2015, 04:06 PM
330drvr 330drvr is offline
 
Join Date: Sep 2009
Location: Clearwater FL
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Default Navworx

Mike:
I am out of town and cannot reference my documents, but the back of the install manual for the Navworx shows all the required connections. I made no changes to the original 327 wiring but did add a link from the 327 to the ADS to pass along the transponder squawk. The pressure altitude link went from my GRT EFIS to the Navworx.
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  #4  
Old 02-12-2015, 06:40 PM
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Default

The 327 only has one serial out port available. When using it to control an ADS-B box like the navworx or the Freeflight it must be set to "remote out" , this setting does not contain altitude data. The ADS-B box requires serial altitude data from an efis (or encoder) as shown in the diagram.

And yes only one source of altitude data is permitted, so if the efis is driving the transponder the same data must be supplied to the ADS-B unit. Same goes if you are using an altitude encoder.
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Walt Aronow, Dallas, TX (52F) RV7A, IO360, C/S, 1500+hrs

EXP Aircraft Services LLC
Specializing in RV Condition Inspections, Maintenance, Avionics Upgrades
Dynamic Prop Balancing, Pitot-Static Altmeter/Transponder Certification
FAA Certified Repair Station, AP/IA/FCC GROL, EAA Technical Counselor
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  #5  
Old 02-12-2015, 06:43 PM
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Mike S Mike S is offline
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Default

Quote:
Originally Posted by 330drvr View Post
the back of the install manual for the Navworx shows all the required connections.
Yep, found that-------but it is not the same as what I linked in post 1.

Quote:
Originally Posted by 330drvr View Post
I made no changes to the original 327 wiring but did add a link from the 327 to the ADS to pass along the transponder squawk.
So, the ADSB sends a squawk code also??

Quote:
Originally Posted by 330drvr View Post
The pressure altitude link went from my GRT EFIS to the Navworx.
So, the transponder no longer sends altitude info, just the ADSB box???
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Mike Starkey
VAF 909

Rv-10, N210LM.

Flying as of 12/4/2010

Phase 1 done, 2/4/2011

Sold after 240+ wonderful hours of flight.

"Flying the airplane is more important than radioing your plight to a person on the ground incapable of understanding or doing anything about it."
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  #6  
Old 02-12-2015, 06:47 PM
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Radomir Radomir is offline
 
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1) Yes, ADS-B sends the squawk.
2) No, the transponder still sends the altitude.. they both do.. hence it should be same value (that's why same source has to feed both).
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  #7  
Old 02-12-2015, 06:52 PM
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Mike S Mike S is offline
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Default

Quote:
Originally Posted by Walt View Post
The 327 only has one serial out port available. When using it to control an ADS-B box like the navworx or the Freeflight it must be set to "remote out" , this setting does not contain altitude data. The ADS-B box requires serial altitude data from an efis (or encoder) as shown in the diagram.
OK, then how does the transponder get the altitude data??

And, what does the transponder "control" in the ADSB box?

Quote:
Originally Posted by Walt View Post
And yes only one source of altitude data is permitted, so if the efis is driving the transponder the same data must be supplied to the ADS-B unit.
But you said above that the transponder cant send altitude data to the ADSB box, as there is only one serial port.

I am not trying to nit pick, just trying desperately to understand how all this goes together.
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Mike Starkey
VAF 909

Rv-10, N210LM.

Flying as of 12/4/2010

Phase 1 done, 2/4/2011

Sold after 240+ wonderful hours of flight.

"Flying the airplane is more important than radioing your plight to a person on the ground incapable of understanding or doing anything about it."
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  #8  
Old 02-12-2015, 07:12 PM
BobTurner BobTurner is offline
 
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Default

Mike,

He said 'no changes' in transponder wiring so I presume he had and still has a serial line from Hx to 327 (not shown in your diagram) for altitude data. And a second serial line Hx to UAT (shown) again for pressure altitude data to UAT. Serial line 327 to UAT carries squawk code (yes, transponder and UAT both send it).
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  #9  
Old 02-12-2015, 07:17 PM
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Walt Walt is offline
 
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Quote:
Originally Posted by Mike S View Post
OK, then how does the transponder get the altitude data??

And, what does the transponder "control" in the ADSB box?



But you said above that the transponder cant send altitude data to the ADSB box, as there is only one serial port.

I am not trying to nit pick, just trying desperately to understand how all this goes together.
1) The transponder will accept serial in or gray code altitude data.

2) The 327 will send squawk code and functional (stby, on, alt) control to the ADS-B box via the serial out port .

Don't get serial in and serial out confused. The 327 has 2 serial in ports and 1 serial out port.

And yes ADS-B sends squawk code and altitude data as well.
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Walt Aronow, Dallas, TX (52F) RV7A, IO360, C/S, 1500+hrs

EXP Aircraft Services LLC
Specializing in RV Condition Inspections, Maintenance, Avionics Upgrades
Dynamic Prop Balancing, Pitot-Static Altmeter/Transponder Certification
FAA Certified Repair Station, AP/IA/FCC GROL, EAA Technical Counselor
Authorized Garmin G3X Dealer/Installer
RV7A built 2004, 1700+ hrs
Website: ExpAircraft.com, Email: walt@expaircraft.com, Cell: 972-746-5154

Last edited by Walt : 02-12-2015 at 07:21 PM.
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  #10  
Old 02-12-2015, 08:34 PM
330drvr 330drvr is offline
 
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Default

Just to clarify, the EFIS sends pressure altitude to both the transponder and the Navworx through separate wires. IE: different serial ports but same info. The connection from 327 to Navworx sends the sqawk code and on off info.

When I am at the airplane on Sunday I can refer to all my wiring records and serial port settings by phone if you like.
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N174MR
RV-7A
IO-360
Dual GRT HX
Dual Adaptive AHARS
GNS 480 Navigator
Dues paid 2017
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