View Full Version : NavWorx ADS-B Connections

Rob Hickman
03-22-2011, 10:33 AM
I installed the Navworx ADSB box this week end. The traffic is amazing, up to 28 targets on Sunday evening while flying over the top of Atlanta Hartsfield. However, the one problem I noticed was that if you looked carefully you would see a yellow target right underneath your airplane, colored yellow. It always matched my altitude, and since I wasn't getting an audio traffic warning, I concluded that it was being presented by the ADSB and not the TIS from the Garmin 330. I spoke with Bill Moffit and ran another wire last night, and configured the ADSB to accept the squawk codes from the Garmin 330 and on this morning's flight the ghost target was gone.
So here is the fix:

Run a single conductor shielded wire from either RS232 1 or RS232 2 of the 330 transponder to pin 33 of the ADSB box. Pin 33 is not documented for this purpose yet, but it works. We are already using pin 7 for the AFS serial altitude out to the ADSB, so pin 7 is unavailable. Configure the 330 for REMOTE + TIS. Then, using the PC attached to the maintenance port of the ADSB send the command TXCP GTX330. You can verify it is working by putting in a code other than 1200 in the 330 and then use the READ ALL command to the ADSB and see the new Squawk code in the ADSB box.

It was NOT fun getting upside down to install this wire to the back of the 330! Hopefully, this will help those who are still in the wiring phases.


04-04-2011, 12:49 PM
I really don't understand how the ADSB box is picking up so much more traffic than what you would normally see for TIS-A in a radar environment. I could understand if you had a couple more since those aircraft could potentially be ADSB transceiver equiped and you wouldn't see them on a TIS-A stream. In displaying TIS-A inly, could it be that your 330 is filtering out those other targets because their not in your "immediate" area? Also, are you viewing composite TIS, i.e. your 330 serially connected to the ADSB transceiver so it can blend both TIS-A & TIS-B together? Are you able to see the difference in the targets in terms of more info that is displayed?

vic syracuse
04-06-2011, 08:24 AM
I am sure that it is a range and distance configuration, which is not configurable within the TIS but is configurable within the ADSB. This week end on the way to SNF and back we could dramatically see the difference due to the setup in my airplane--- 2-4500's and 1-3400. The 4500's support both TIS and ADSB, but the 3400 only displays the TIS. At least that's what I noticed on the trip. We could see many targets on the ADSB and only 1 or sometimes none on the TIS. The TIS is a much closer view, agreed. But I sure like the longer range view of the ADSB, especially inside the Atlanta Class B where the jet traffic is moving so fast.

04-06-2011, 10:12 AM

I've been following your recent postings on here and VAF. I'm putting in a couple 4500s and a 3400 too. I asked Trevor about compatibility between the two as was led to believe that the 3400 could display anything the 4500 could, the only difference was the menu trees and control input (i.e. buttons and knobs). Your post indicates a different result. Are you finding anything else other that ADS-B that won't display on the 3400?


Trevor Conroy
04-06-2011, 04:37 PM
TIS-A is limited to 12 targets where TIS-B can have up to 32. It has to do with the hardware more than anything.

The ADS-B weather and traffic will work on all of our s-cpu units.

vic syracuse
04-07-2011, 10:01 AM
Bob, I wouldn't talk you out of your setup, as that is what I have. I don't have the S cpu in my 3400, so that might be making the difference, too.


Trevor Conroy
04-07-2011, 10:38 AM
That is correct, non-s CPU units cannot take advantage of the ADS-B box. ADS-B wasn't available when we were manufacturing the non-s units.

08-04-2011, 11:39 AM
Have talked to Navworx and cant determine if I will have an issue on ghost target with garmin320 transponder,analog version. Anybody know?

08-27-2011, 06:58 PM
I have connected a NavWorx box to my 4500. In the Minneapolis area I get TIS-B up to about 30 miles from Minneapolis and after that all the traffic disappears. I'm wondering if this is a problem with my installation (perhaps signal attenuation between the NavWorx box and the antenna) or is this just that there isn't much coverage yet in MN?

I really like the traffic depiction - the motion vectors really help visualize the direction of traffic. And the times I've actually seen the targets outside the cockpit (amazing how many I couldn't see) they were right where the display showed them relative to me.

I have seen up to 16 targets but no more, is the 4500 limited to only 16 or is this just a coincidence?

Mark Olson F1-EVO Rocket

08-28-2011, 04:53 AM
I have connected a NavWorx box to my 4500. In the Minneapolis area I get TIS-B up to about 30 miles from Minneapolis and after that all the traffic disappears. I'm wondering if this is a problem with my installation (perhaps signal attenuation between the NavWorx box and the antenna) or is this just that there isn't much coverage yet in MN?

Hmm, if you look at this chart, you should have plenty of coverage. http://navworx.com/PDFs/ADS-B_coverage_map-mt.pdf

What transponder do you have? If you have a GTX-330, it appears that you may be getting TIS-A from the transponder and not the TIS-B. Although I would think that should be further than 30 miles too. Obviously, I'm just guessing here.

What is MAXDIST and MAXALT set to?

Are you getting the FIS-B?

Let's us know what Bill @ Navworx says when you give him a call.

I just got mine on Friday and am just in the process of installing it. I'm not flying yet, so I have no experience other than reading the manual many times.


08-28-2011, 03:57 PM
I am seeing the FIS-B data as well. I don't have a Mode S transponder so all traffic is coming from the NavWorx box. I do not remember what the MAXDIST and MAXALT parameters are set to.
What seems to happen is when I take off from FCM I get traffic almost immediately upon climbing. It disappears somewhere 20-30 NM from MSP. Upon coming back to the MSP area, I often don't get traffic until I am a lot closer to MSP than I was when it originally stopped - sometimes almost on top of FCM. I think I am getting FIS-B information before I see any traffic.

I've never seen traffic displayed anywhere other than what I described above, and so far the max I have seen is 16 targets.

I am going to recheck my cable from the NavWorx box to the antenna. It's possible there's a problem, such as a short, causing it to attenuate the signal and hence dramatically reducing the range. I do know that I enabled the transmitter, so that's not the problem.

I've also seen another graph somewhere showing the location of ADS-B ground stations. It only shows 2 of them in MN, one at MSP and another to the southwest (perhaps MKT?). It sure doesn't look like the state has a lot of coverage at present. The FAA ADS-B site only shows what the coverage is projected to be by 2013, so that information isn't terribly useful. So I am confused about what the ADS-B coverage in MN really is at present.

Mark Olson F1-EVO

Trevor Conroy
08-29-2011, 08:28 AM
It sounds like you are only getting TIS-A information if you loose traffic 30nm from MSP and are only getting 16 targets. I think that is the max the GTX-330 will output. You may want to call NavWorx regarding this.

Regarding the ADS-B map on the FAA website; it isn't quite 100% accurate. On the way to OSH from Oregon, we lost ADS-B once we hit Eastern OR and didn't pick it up again until getting to within about 50nm of MSP. It worked from that point all the way to OSH.

08-29-2011, 10:13 AM

Traffic can't be coming from a Mode S transponder because Mark said he doesn't have one. Taking a wild guess here, but I wonder if the ADSB site is not fully TIS-B functional so they are re-broadcasting TIS-A traffic as TIS-B thus explaining the limited range that you would get with TIS-A?

Trevor Conroy
08-29-2011, 11:33 AM
It is possible that he isn't using a full serial port either and is just using the TIS output from the ADS600-B. The DISPLAY port in the ADS600-B manual should be wired to one of our serial ports (usually Port 3). If he is just using the TIS output, it will only send TIS-B data rather than both TIS-B and FIS-B.

08-29-2011, 05:43 PM
I used serial port #3 for the TIS output. It very well could be that there were not more than 16 targets at the time I looked at it. However, I am still puzzled at the lack of range for the traffic. I am getting METARS/TAF/graphical WX data - but am not sure of the range I'm getting with these. On my flight from MSP to Duluth I lost the WX products somewhere along the way, I suspect a little further out than the TIS data, but it's not quite the coverage I expected.

I have not yet flown east of MSP so I don't know what I'd get for traffic reception in that direction. I can now compare what I receive to what I know others have seen - TIS all the way from MSP to Oshkosh. I do know that traffic disappeared quickly once I moved south from FCM.

Trevor Conroy
08-30-2011, 08:26 AM
It sounds like the wiring is correct then. I think it is just a coverage issue. ADS-B doesn't go very far West of MSP as of right now.

09-07-2011, 12:09 PM
I was flying on Saturday and saw 17 targets, so the 16 limit I saw was a coincidence. I got info from NavWorx that TIS-B is limited to 15 miles, but wasn't certain if that was 15 miles from the aircraft or from the center of the coverage area. I did fly southeast from MSP but at a lower altitude (3500 MSL) and the coverage went away at about the same distance from MSP as I saw to the west. The AFS4500 outlines the ADSB info in yellow when coverage is lost, so it's easy to tell that apart from when there are just no targets in range. I will try a more extended flight east of MSP at a higher altitude to see if I keep coverage further in that direction.

Mark Olson F1-EVO Rocket

Trevor Conroy
09-08-2011, 08:36 AM
At 3,500 you are limiting yourself on coverage. The ADS-B stations are line-of-sight, so the higher you are, the further it is going to work until you hit another ground station. Try going higher and doing some testing East of MSP.

09-08-2011, 01:08 PM
Last night I flew east of MSP to about 20nm west of Eau Claire, WI, at about 8500 ft. I lost ADSB about 15 miles from MSP and did not get it back again until I got close to FCM.

It's somewhat difficult to tell if ADSB is working or not - I based my above statement on the fact that WX did not refresh until I got back within range of MSP. I have checked the coaxial cable between the UAT antenna and the box, and it isn't open or shorted, but perhaps it's attenuating the signal in another way. I may try to make another cable just to see if this resolves the problem.

Mark Olson F1-EVO Rocket

09-09-2011, 11:09 AM
In July, we flew from Oklahoma to California (San Francisco area). From Eastern NM all to way to and back from CA, we had traffic about 80 to 90% of the time. We had WX only 2 times and that was for about 2 to 3 minutes each.
I am not sure if they are transmitting WX all the time.

PS: We have In-n-Out.

Trevor Conroy
09-09-2011, 11:15 AM
Gary, if you go to the ABOUT page (CHECK -> MAINT -> ABOUT), it will show the age of all the WX data as well as the number of WX packets received.

07-08-2012, 11:38 AM
I'm finishing up wiring my ADS-600B to my 4500 and GTX-330 and I'm confused by the pin call-outs in the "ADS600-B to AFS Interconnect Diagram". I understand the need to connect pin 33 on the ADS600B to one of the RS232 out pins on the transponder for remote control, however the diagram also calls for connecting pin 35 to "Transponder Suppression Input" but dos not provide what pin on the transponder to use (I'm assuming by the description it connects to the transponder). I find no other reference in the newest install docs and don't know what it's purpose is. Anybody know?

Got an email response from Bill Moffitt and he said that pin 35 on the ADS600B does in deed connect to pin 31 on the GTX-330. This is required so that both don't try and transmit at the same time.

Also another tidbit regarding composite TIS. Bill says don't waste time trying to setup for composite TIS since anywhere there is TIS-A, there is now TIS-B. Composite TIS is a old feature that is no longer needed and not worth the extra wiring.

Rob Hickman
07-10-2012, 10:34 PM
Do you have it connected using the TIS interface or the display port like our manual shows?

The EFIS does not limit the number of targets, the ADSB box might be doing it. I just updated the AF-5000 manual with the Navworx software and it should be the same as the AF-4500.

07-17-2012, 11:19 AM

Yes, I have serial #3 connected to the display port as shown in the manual.

04-21-2013, 12:47 PM
I'm installing the Navworx ADS 600 with an AFS 3500 and 4500 and GTX 327. I understand the serial connections in/out. I also see the post with connection of the ADS 600 pin 35 to the xponder suppression pin. On the GTX 327 this is pin 17. I don't see any reference to programming the GTX 327 for the suppression function. Is there any programming of the GTX 327 required?
I have all serial ports used on the 4500 so I am connecting the ADS600 to the serial ports on the 3500. As I understand it in order for the ADS-B to display on the 4500 I need to transfer the port characteristics to the 4500? Or is this only when updating system software?
Also it took me awhile to find the procedure for getting to the 3500 and 4500 configuration screens. There is reference on page 70 to 'instrument calibration' but no reference as to the button push sequence to get there. Finally found it in appendix J.

In reviewing the GTX 327 pinouts and config for serial out there is no REMOTE + TIS setting for the GTX 327 serial 1 out. Only ICARUS ALT and REMOTE are options for the port. The ADS600 appears to have a config command for the GTX 327 according to the AFS system manual p. 50. Is there/what is the solution?

04-22-2013, 05:50 AM
Timely question as I'm about ready to install my ADS600B as well this week. I just realised that I had all the settings for this one as well.

Since the GTX327 doesn't know about TIS, that's not an option. If you look at the NavWorx manul on the ADS600B to GTX 327 interconnect document page, it does talk about the altitude encoder, but doesn't specifically mention setting the port to ICARUS. I think ICARUS is the correct setting. I suspect that the ADS600 just needs some method to validate what the 327 is transmitting to eliminate it as a potential traffic alert.

Rob Hickman
04-27-2013, 01:40 AM
1. The ADS600B will only work with a "S" CPU (AF-3400s,AF-3500s or AF-4500s) It will not work with the older non "S" AF-3400 or AF-3500.

2. The RS-232 serial line from the GTX-327 to the ADS600B is for setting the Transponder code in the ADS600B. When you enter a code on the GTX327 it sends the code to the ADS600B.

3. I do not believe that there is any programming needed for the suppression line, you should check with Navworxs.

4. You should not have to do any serial port settings on the screen that is not connected to the Navworx unit.