AIS as a GPS Source for an MFD

[pateco]

I am still working on getting my used Raymarine C80 installed, and up and running. I need a GPS receiver which did not come with the unit. I recently read an article in SAIL that noted that several of the AIS transceivers on the market also had built in GPS. If networked to my C80 MFD can one of these AIS trancievers give me both AIS capability and GPS for my C80? I would love to kill 2 birds with one stone.

 

[dlochner]

Check the Vesper Marine XB8000. It has a gps and will translate NMEA 0183 to NMEA 2000. Also has a built in anchor alarm and SAR alarms. Has built in wifi and supports up to 5 iPads, phones, computers. Also had USB connections for computers. Very nice unit. Shop the price, Defender often has it on sale.
XB-8000 Class B AIS Transponder with WiFi | Vesper Marine

 

[Ken13559]

I use Vesper XB8000 AIS transceiver and wired it's NMEA0183 GPS out to my SH GX2150 for the radio ais and dsc function. Works great.

 

[bgary]

+1, Vesper Watchmate Vision here, works great.

 

[uncledom]

I was thinking about one of these. It's cheaper here.
http://www.milltechmarine.com/Vesper-Marine-XB-8000-AIS-Transponder-with-WiFi_p_247.html

 

[jssailem]

It's cheaper here.

Milltech folks are great.

 

[justsomeguy]

That milltechmarine site is a wealth of information.

 

[LeslieTroyer]

check over on the Raymarine forums -- Chuck over there is great at answering these type questions - For AIS I would want something faster than 183 - I have the AIS650 - haven't used it enough to see how I like it - but installation was a snap with it hooking into the SeaTalkng network and power. Raymarine.com->support->Raymarine forum->AIS.

It is $30 more (anchorexpress.com) than the unit referenced above - but I find keeping to a single vendor often simplifies things greatly.

 

[uncledom]

AIS takes two minutes to refresh. How fast does the bus have to be???

 

[bgary]

AIS takes two minutes to refresh. How fast does the bus have to be???

I won't claim to know the full answer to that, but a datapoint: when I connected my AIS to my at-helm chartplotter, I needed to change the NMEA-0183 settings on the chartplotter from standard (4800 baud) to "high speed" (38,400 baud). Both sides need to match for the conversation to happen and the AIS needs the higher rate in order to process more sentences in reasonable time.

Net result is that the AIS targets show up on the chartplotter at the helm, and the chartplotter processes CPA and CTA alarms. Quite useful.

 

[LeslieTroyer]

AIS refreshes at a variable rate - up to every 2 seconds for Class A transverse - every 30 seconds for Class B. In addition to GPS coordinates - you need to send course, speed, Heading, MMSI, Name,Call Sign and Vessel type. Then at lower frequencies - voyage data. At 4800 baud - that is roughly 480 characters/second - with each NMEA sentence taking ~100 characters your looking at only 4 boats per second - assuming no other traffic (i.e. GPS updates). At the faster rates mentioned above (you are not technically using 183 anymore) you get 8 time that or 32 boats which is reasonable - NMEA 2K (Seatalkng) is roughly 52 times the slow 183 rate -