Help please linking PAW to Funke TRT800H for ADS-B Out

[sdkellner]

I have PAW Classic bought a week ago and running the latest software.  I installed it into my MT-03 gyrocopter yesterday with the unit and aerials installed behind the instrument binnacle and within the GRP nose connected to the GPS mouse which sits on top of the binnacle and behind the windshield with a clear view of the sky; it was able to see 11 satellites within the hangar!  My ATR833 radio aerial is also within the GRP nose enclosure and works fine so I assume that attenuation through GRP is minimal. The weather has been too poor to test fly, but on the ground it is seeing plenty of traffic so seems to be working OK.

My challenge is connecting it to my TRT800H transponder in order to achieve ADS-B out.  The transponder was installed under a year ago and is hardware version 6.1 with software version 5.3.  The Funke manual is a little unclear but I think my D-sub connector is the TRT800EMSS because the cables coming from the connector match the wiring diagramme under section 3.7.3.3 of the Funke manual.  However, the connector itself has ‘EM800’ on the label with no reference to EMSS; I have asked Funke for clarification but have not heard back.

I purchased the recommended RS232 cable from Farnell as here http://uk.farnell.com/ftdi/usb-rs232-we-1800-bt-0-0/cable-usb-a-rs232-serial-convertor/dp/1686450.  I was then faced with the conundrum of which cable to attach to which; after much research I have crimped orange USB to light brown transponder, and black USB to bare transponder – see attached pictures.  I was not entirely certain as to which of the two brown transponder cables to connect; I went with the less obviously brown one because it was contained within the grey cable sheath whereas the other clearly brown cable was outside of the sheath along with the red and blue power cables, so I took this to be the auto-on pin 14 connector and left it well alone.  I made the connections via crimping, which I have not used before and may therefore be the source of my problem.

The RS232 USB cable was connected to the top left USB port of the PAW (with the Ethernet port immediately to the left) which I understand is Port 1, so I selected ‘Funke’ and 4,800 baud for this port on the PAW configuration page and saved.  On the TRT800H set-up screens I enabled RS232 and selected ‘NMEA’; the baud rate appeared as 4,800 but position reported ‘No data’.  I tried rebooting the PAW and recycling the TRT800H to no avail.  Thinking that perhaps the top left port isn’t port 1 after all I then cycled through amending each port to Funke/4,800, but still the TRT800 showed ‘no data’ at the position field.

I was powering the PAW via the official lead from an Anker Power Core 20100, although inflight I intend to use an Anker dual USB cigarette socket adapter. 

Can anybody spot an error in my setup?  Might I have connected the wrong leads?  Can I interrogate the PAW’s GPS output via data logging to check all is OK there?  Might there be a fault in the RS232 cable?  Or might I simply have a poor crimping connection?

Photos hopefully attached to show the various parts of the setup.

Many thanks.

Stuart

[Admin]

Hi Stuart,

Somebody asked me to post their findings anonymously regarding the TRT800, this may be useful :-

Hi - I hear you're after advice on PAW to TRT800 for ADSB-OUT - I've had some level of success with this (as far as I can tell anyway!) but haven't recently used it because our transponder is running too old a firmware to be upgraded. It appears to all work but doesn't set the SIL/SDA to zero so _technically_ shouldn't be used.

So first there is the RS232 (9pin) to USB cable you need. On Lee's advice I bought this one (I think) which seems to work fine and is cheap!:

http://www.ebay.co.uk/itm/USB-2-0-TO-SERIAL-RS232-DB9-9-PIN-ADAPTER-CABLE-PDA-cord-GPS-CONVERTER-SF-/111671837924?hash=item1a002904e4

Then setup the appropriate USB port as Funke Transponder for this on the PAW config page.

On the transponder side, you need to get into the setup and set the format of the incoming messages to "NMEA" and 4800 speed (or this may be the default or only option anyway - I forget). From memory the way to get into the menu for this was a somewhat strange holding down of a button (ID?) for something like 47 secs or something! - all very odd. Look in the manual for your transponder. There seems to be a lot of different versions of this transponder btw!

Now, the cable you already have in your aircraft that is supplying power to the transponder can be one of 3 kinds I think :

1) The newest, fanciest is one that has some sort of remote control functionality. Not seen this type in the real world but I think it's the same as the 2nd type below but the black is a brown wire.

2) The 2nd type is one where the RS232 wiring is included. For this type, you just need to connect the ends to a female 9 PIN RS232 socket:

   WIRE          9 PIN FEMALE CONNECTOR

   Shield ------ PIN 5&9 = GND
   Black  ------ PIN 3   = TX
   White  ------ PIN 2   = RX
   
Technically you don't need to connect the last one as we're only interested in transmitting INTO the transponder.

3) The 3rd type is the simplest and biggest pain - and what I found that we had. This is a very simple cable with no connection for RS232 just 2 wires for powering the transponder.
Technically what you should do now is contact Funke and buy their £100 cable with the RS232 connections and replace your existing simple power cable.
Being cheap I didn't do this :-)
Now there is a another strange thing to know. The settings for the Funke (e.g. callsign for the a/c etc set in the setup menu) are stored in the cable, not in the transponder! Yes that's right! The 'reasoning' here is that you can swap the transponder and keep the settings 'attached' to the a/c in the form of the cable!!
Basically there is an EEPROM inside their cable! I didn't want to hack at the connector / existing cable to try and hook in the RS232 connections so this presented me with a dilemma. I looked into the idea of buying a compatible EEPROM and building one of these 'smart' cables, wiring that up and seeing if it all worked - but then it dawned on me what I could instead ...

What I did was create a cable with a 15 pin female connector on one end (plugs into the transponder) and a 15 pin male connector (plugs into our existing transponder power cable removed from the back of the transponder) plus a female 9 PIN RS232 (plugs into the EBay cable) on the other end. All pins are wired straight across from the 15 pin female to the 15 pin male, except the RS232 ones which are wired as explained above to a female 9 pin RS232. Voila! Connects and uses the chip in the existing simple cable without so much as unplugging the existing wiring!
 

Regards,

[sdkellner]

Hi

Thanks for this.  I think I have the newest type of cable referred to as point 1 by your contributor, the TRT800EMSS (although as I mentioned in my post it's not clear so this is only my deduction by comparing the wiring with the manual), whereas it sounds like he has the older version and so his wiring would be different from mine.  My transponder setup has already been done as he describes (you have to hold down 'ID' when in standby until 'Enter Setup' appears; takes about 20 seconds as it cycles through FID, Change FID, Show Setup first).

I'm pretty sure that I followed the instructions within the PAW and Funke manuals and additional sheets to the letter, although I'd really appreciate input from others with the TRT800H.  At the moment it looks like my problem is likely to be, in descending order of probability :-

1. Poor crimping connection.
2. Wired the wrong cables together (can anyone with a recent TRT800H with the EMSS module confirm which brown to wire to the RS232 orange TX?)
3. Incorrect PAW setting (perhaps wrong USB port?)
4. Faulty RS232-USB cable.
5. Incorrect transponder setting.

Best

Stuart

[sdkellner]

Funke have just confirmed that I definitely have the TRT800EMSS connector, as I'd guessed; wiring diagramme attached if this helps anyone.

Stuart

[Admin]

Hi Stuart,

So sounds like you have the wiring correct.
(TRT800) Brown / RxD, connected to
(RS232) Orange / TxD

The only way of _really_ testing what is being output from the RS232 TxD, is to connect to an RS232 input and run a terminal emulator program such as PuTTY on a PC, this will output the data.

One of your earlier questions regarding ports, you are correct the top left as you look end-on, is port 1.
I think you have everything configured correctly.

Thx
Lee

[sdkellner]

Hi Lee

Thanks for the reassurance.  I'm still not entirely convinced that I have wired up the correct brown out of the two browns from the TRT800H, although I think the most likely issue is a poor crimping connection - the wire from the RS232-USB lead in particular is very narrow gauge.  I think I might try again with a small junction strip connector or possibly solder.

Truly amazing kit, the PAW; really looking forward to flying with it.

All the best.

Stuart

[Ian Melville]

For the purpose of the test, just twist the wires together.  If the crimp is too big for the wires then twist as just mentioned and slide crimp over so both wires go in same end. If you think ahead then some heat shrink that fits over the crimp and wire can make it all look line a neat inline crimp.

[sdkellner]

Thanks Ian; great advice.

I'll try and get over to the airfield over the next few days and have another go.  I will report back.

Stuart

[exfirepro]

Hi Stuart,

I have been following this thread with interest, but as I run my ADSB out from a Trig TT21, I can't help you with the 'Funke Specific' bits and Lee has already clarified the wiring for the FTDI leads (which I have used for both ADSB Out and FLARM-In with PAW).

I just wanted to let you know that when I initially fitted my transponder a couple of years back it initially wouldn't power up. A quick check showed that my overzealous use of the crimping pliers had caused the crimp to cut right through the very thin main power cable, which was still being held in place by the outer part of the crimp gripping the insulated part of the wire, so not immediately obvious, but nonetheless open circuit.

I would therefore definitely check your crimped connections and support Ian's suggestion to try a simple twist to connect the wires for test purposes. By all means use solder to complete the joints, but do so very carefully as soldering can make thin wires very brittle!

Looking forward to hearing that you have managed to sort out the fault and got everything running.

Best regards

Peter

 

[sdkellner]

Thanks Peter; it's looking increasingly likely that my crimping might be to blame.  I certainly exerted some pressure as I wanted to make a secure connection.

I hope to get over to the airfield on Thursday to try changing the connectors; I'll report back.

Best

Stuart

[daviddurrans]

Hi Stuart,

I've done this with a Funke try 800.

Basically it's the orange wire on the Farnell cable to brown on the Funke cable, and black (ground) on the Farnell to the ground or screening on the Funke. As you say there are 2 browns on the Funke side. Make certain you are using the PIN 12 brown (not the pin 14) The Funke manual shows the pinning on the plug that goes in the back of the transponder. A multimeter helps here to check which is which but it isn't essential.

The no data issue: Mine does this if I don't turn the transponder on first, then the gps and then give it plenty of time to acquire satellites. If it shows no data then you end up switching everything off and starting again

Hope this helps

David

[sdkellner]

Good news... ADS-B out is now working fine 

As I think we all suspected, the problem was my crimping - I rewired via small junction boxes and my TRT800H then reported coordinates in the position field.  I took to the air and Hawarden and Liverpool reported good ADS-B data.

My original wiring was correct - orange RS232-USB data out to light brown RX (within the grey sheath) of the TRT800H; black RS232-USB to bare ground within grey sheath of TRT800H.

Some other issues during the flight which I need to work on - traffic would occasionally disappear from SkyDemon, no non-ADS-B traffic appeared at any time, despite the beta filter setting being enabled - so I was aware of the Beluga into Hawarden and the RYR/EZY traffic in/out of Liverpool, but not the PA38 that crossed my path half a mile ahead; occasional interference on the radio which I assume to be from the PAW audio out (went away when I disabled my intercom external input); GPS signal lost three times during flight, which I think was due to wifi problems between my iPad mini 2 and the PAW - when using the iPad's own GPS it never loses signal.

Many thanks for all your help; this certainly has the potential to be an amazing product.

Stuart

[Ian Melville]

Stuart, Did you configure SkyDemon to display Bearingless Targets?

If you WiFi is dropping out, try reducing the power to minimum, especially if the units are close. Also, try other WiFi Settings. But before you do check that you PAW was not rebooting by looking at the up-time. If it matches the last loss of GPS, then you possibly have a power issue.

[sdkellner]

Hi Ian

Yes, I had bearingless targets enabled on SD - I double-checked this in flight.

I will try your suggestion of dropping wifi power; the units are maybe 18 inches apart.  I didn't check whether the PAW had rebooted; will check next time.

Thanks for your help.

Best

Stuart

[exfirepro]

Stuart,

What settings do you set have on the PAW Configure page?

You say you aren't seeing any Mode C/S targets, despite having Mode C/S detect set to 'Mode C/S Beta' (+ Filter if you have a transponder). It may just be that there were none within range.

I would set Mode C/S Range to 'Medium' - or even 'Long' Range in the first instance, reducing this to short range if you are getting an excessive number of Mode C/S alerts.

And remember to click 'Save' to store these settings.

If traffic is 'disappearing' suddenly, this is most likely to be an antenna position issue.

Re the audio interference and loss of gps, this sounds to me more likely to be a power supply issue. In my (considerable) experience, unless badly sited, PilotAware GPS is generally significantly more reliable than iPad or other tablets internal gps.

Finally, remember the PA38 may simply not have had a switched on transponder - or it could have been Mode 'A' - which PAW can't show.

Regards

Peter