AIS data

Hello,
I am currently working on a 60' Falcon that has a NN VX2 setup. One of there FI30 died and they requested that all instruments be upgraded.
Their setup includes...
Main Wheel house:
2x VX2 chart plotters, Radar Array, ETR Sounder OceanTalk 700 AIS, AP 3003 gold AP, IF8810 module, FI5002 Jun Box, NMEA 2K converter, 2x FI50 Tridata, 1x FI501

Fly Bridge
1x VX2 Plotter, 1x FI50 Tridata, 1x FI501.

All plotters are networked through a DLink switch.
There is a diagram attached.

The issue is. The AIS will show contacts for around 40-60 sec then disappear and alarm. This will occur on all Plotters. The AIS is attached to the Stb side Plotter (non Master) while the Port side is the master display all Data ports are used (please see diagram). If I remove the cables from the Port side plotter the AIS will stay on all screens. I have even tried connecting one cable at a time and retrying...stops showing/sharing AIS.

Data 2 on the Port side is being used with for other NMEA183 equip. These are connected in a Junction Box (in a sense wires tied together, not through a Multiplexer)

Not all cables are accounted for.

I apologise for any confusion in writing and diagram. I have gone through our Furuno dealer here but they are running out of things to try, the job is stretching out.

Thanks in advance for any responses.

Very good posting of information. Normally if AIS has problems; it is normally related to older software or poor data flow design (typically data loops)

Reviewing your setup, I would make the following suggestions.

- Make sure all NavNet units are running the same and most current software. (4.01 Navionics or 4.03 C-map)
- Ensure that you are NOT sending heading or auto pilot sentences over the network from the master unit. (heading goes over the network automatically as part of radar information and turning it on results in data looping)
- Ensure if running Navionics charts that you are using XL9 format maps, because many larger GOLD formats are not compatible and will bog down the machine. (can always test with no map cards inserted)
- Both main units appear to have GPS wired to them. Ensure that only one of those two units have GPS data turned on over the network. The other and the extra "slave" should not also send gps to network or again data loop issues.
- Beware if the IF-NMEA2k2 converter is wired bi-directional because it could also result in a data loop.
- FYI..for you drawing...Data 3 on the master radar unit is heading. Heading data is the only thing that port can be used for.

Hi Johnny,

Thank you for your reply.
-At this stage I can not update the software and it is not up to date (3.04), but all three plotters carry the same C-Map version.
-We have turned off the Network (NMEA DATA) from the two slave units, I will check to ensure on the master that the heading sentences are turned off as well.
-If I remove the Cable (port 4) from the Stb side (slave) it will alarm with 'No Heading' this confused me as I thought it should get it over the network.
-I did set up the IF-NMEA2k2 as bi-directional, so I will remove the Tx pair.
- I have updated my drawings to reflect Data 3.

Since your reply I haven't been back on the boat as I am waiting for the skipper to call to organise this.

again thank you for your feedback.

If I remove the Cable (port 4) from the Stb side (slave) it will alarm with 'No Heading' this confused me as I thought it should get it over the network.

Click to expand...

It appears that NMEA heading is going into port 4 on this unit. THIS is a very BAD thing. Heading is only ever allowed to go into the dedicated heading port (or from the radar unit as part of the radar data). If you place heading data on the normal NMEA ports it WILL cause you problems. I also recommend checking that heading numbers show up on the radar screen of your master unit.

Because of changes of AIS over the years (for example of the addition of class B AIS in 2009) it is VERY important you get the software upgrade on the units to current software.

Have been back on, and looks to be resolved.

I have removed the Tx pair from the converter, turned on the system and no loss of data.

The SW will be done at a later date.

Thanks for your assistance Johnny.

:jump