IF-NMEA2K2 not communicating with AP22 autopilot

[Storfisk]

Hopefully someone has a quick fix. I have installed an IF-NMEA2K2 drop on the operating NMEA2k backbone with hopes that I could send and receive waypoint output data to and get heading data from my Simrad AP22/j300x autopilot. The Simrad will output heading (HDG) at 10Hz (= 100ms) so in theory that should be fine for radar overlay.

The interface device is recognized on the TZT3 sensor list, its amber light flashing, it appears on the data source page although no data present, and I have PGN's 129025, 026, 029, 283, 284 and 285 turned on.

I wired the IF-NMEA2K2 wires to the Simrad j300x terminals as follows:
Pink to TB10 RX2+
Pink/Black to TB10 RX2-
Blue to TB10 TX2-
Blue/yellow to TB10 TX2+

I get no heading data going into the TZT3 nor does the AP22 receive waypoint data from the TZT3 via the IF-NMEA2K2.

So dumbfounded I ran a few checks.
First, I hooked only the converter NMEA 0183 output leads to my radio and no Lat Lon data appeared.
Second, I hooked the TZT3 NMEA 0183 output from the multicable to my DSC radio with the GLL and APB sentences turned on. The radio received the Lat/Lon and time data fine.
Third, I ran a loop test on the Simrad NMEA 0183 connections jumping the output to the input and it checked OK. I then connected the multicable NMEA 0183 output from the TZT3 to the Autopilot NMEA 0183 input TB10 RX+/- and the Go To heading data from the TZT3 was present on the Autopilot. The Baud rate set at 4800, the NMEA version at 2.0. Unfortunately, there is no way for me to double check the Simrad output other than the jumper test I did.
I'm hoping someone has successfully integrated an older Simrad AP into the latest generation of TZTs via IF-NMEA2K2. Maybe I've overlooked some step to jump start this darn thing? Or am I chasing something un-attainable with the IF-NMEA2K2?

I know a (amazing) SCX-20 would solve my heading issue as well a smooth out many other things, but that is not in my budget right now.

 

[Bayhouse]

On the TZT3, what have you selected as the source for heading data?
On the AP22, is there a Sources setting in config?

 

[Johnny Electron]

So this pilot only has 0183 support? If so, the best configuration would be to put the IF-NMEA2k2 into high speed heading mode and wire the Simrad heading so that it drops to the 2000 bus for the Navnet. (ensure matching baud rate) Then take the 0183 output wires offered by the NavNet MFD over to the simrad input for providing the steering instructions. Of course you would need to configure the sentences you wish to output and as Bayhouse stated, you must select your sources in both the pilot and the Navnet. Using the converter in normal mode can work but the quality and speed of heading is going to much slower and the proper PGNs need to be sent out and the sources need to be selected.

 

[Storfisk]

Thanks for the reply.
The AP22 is only 0183, it’s that old.
The TZT3 has IF-NMEA2K2 as the heading source and the Simrad has NMEA (input/output) 2 as the source for wiring and GPS1 as the device.
I’ll try the high speed, cutting the orange wire and see if that helps when I get back to the boat.
It still bothers me that I could not get a direct connection through the converter with only the radio but I’ll just leave it connected to the TZT3 0183 output so at least I have DSC calling in order.
I’m sure I’m doing something wrong on my end so thanks again for the help.

 

[Johnny Electron]

Always make sure you have matching baud rates. Also know when you change modes on the IF-NMEA2k2, you should power it up for a few seconds to see the mode change, then remove it and put it back on to implement the mode change. If you cut the wire and just plug it in, it won't work unless someone cycles the bus power. It needs to be power cycled after any mode change.

 

[Storfisk]

Good to know, thanks.
I’ve also tried different sequences of powering up devices and network in various orders.
Hopefully in due time I’ll have some good news.

 

[Quitsa]

I had one of those a million years ago. I believe you need to use NMEA output from Port 2 on the controller, which is the one that is intended for sending out heading data at the proper baud rate for radar overlay. The baud rate settings need to match up of course. I know it can be made to work because I had mine set up that way.

 

[Johnny Electron]

Quitsa reminds me on some of the older simrads with "Simnet" that sometimes you can't get anything normal to speak to them at the processor unless you have their Simnet to 0183 converter (which they don't sell anymore) or like Quitsa said many of their control head had a NMEA port on the back. If you have one on the back of yours; that is the place to connect up to. That is most likely the entire problem. Proprietary Simnet was a bit tricky that way.

 

[Storfisk]

I'm beginning to get the feeling that yes this is not going to work.
I am making the connections to the NMEA 0183 (#2) inputs and outputs on the J300x. It's odd that the AP will accept the NEMA 0183 output directly from the TZT but not from the IF-NMEA2K2 at 4800 baud. Almost as if the device does not work.
I did try the faster baud rate to see if heading would come into the TZT with no success.
So, at this point I guess it was not meant to be. Maybe I should have first tried an Actisense? Seems to me the Furuno 0183 is not in line with the Simrad 0183. Maybe it's just that the NMEA version does not line up? For ha ha's I'll try the direct NMEA 0183/3.0. If that does not work while 2.0 does, I'll bet that is the issue in that the IF-NMEA2K2 uses the latest version.
Well maybe Santa will put a SCX20 under the tree.
Thanks to all for your suggestions.

 

[Quitsa]

I'm beginning to get the feeling that yes this is not going to work.
I am making the connections to the NMEA 0183 (#2) inputs and outputs on the J300x. It's odd that the AP will accept the NEMA 0183 output directly from the TZT but not from the IF-NMEA2K2 at 4800 baud. Almost as if the device does not work.
I did try the faster baud rate to see if heading would come into the TZT with no success.
So, at this point I guess it was not meant to be. Maybe I should have first tried an Actisense? Seems to me the Furuno 0183 is not in line with the Simrad 0183. Maybe it's just that the NMEA version does not line up? For ha ha's I'll try the direct NMEA 0183/3.0. If that does not work while 2.0 does, I'll bet that is the issue in that the IF-NMEA2K2 uses the latest version.
Well maybe Santa will put a SCX20 under the tree.
Thanks to all for your suggestions.

You may be on to something in thinking the issue may lie with the IF-NMEA converter. If you are using port 2 on the J300X and you have it set as instrument output, it should be putting out the heading sentence. I know for sure that works because I had mine set up that way. Too bad the TZT 3 doesn't have a native NMEA 083 input. I guess you don't have a serial connector that would allow you to see the NMEA 0183 sentences on the port?