AIS Signal Splitter to 2 Laptops

[Colin Stone]

Can an AIS signal be split to feed 2 laptops via USB?? I currently have the AIS signal feeding 1 laptop but wish it to feed into 2 laptops using USB.

[pteron]

What output form does the ais unit use? USB is point to point and not a broadcast protocol so I'd be surprised if you can do it.

[sded]

AIS usually outputs a fast NMEA (38.4kbps) serial data stream. If you are using it now with a serial-USB converter on one computer, you should be able to get another converter and provide it in parallel to the second computer as another serial data stream just by branching the signal. That's what I do to share AIS between a computer and a chart plotter.

[pteron]

That's interesting, is it RS232 serial?

[sded]

My current AIS1000 actually puts out both rs232 and nmea (rs422 differential) for AIS. Previous SR was just one RS232 output. Newest nmea 0183 standard is actually rs422, but most people ignore that and use an rs232 connection by connecting the + lines as signal in/out and grounding the - lines together.

[pteron]

Thanks for the info. RS232 and its ilk would be much easier to split than USB!

[gmau]

Originally Posted by Colin Stone

Can an AIS signal be split to feed 2 laptops via USB?? I currently have the AIS signal feeding 1 laptop but wish it to feed into 2 laptops using USB.

It looks like the AIS puts out NMEA 183 RS232. You need to contact the AIS manufactor and find out how many loads the output of the AIS will handle. Most can handle two. If it can handle two, then you can run the output of the AIS to both computers.

Gordon