Using the Comar AIS-MULTI, Vesper Marine AISWatchMate and GPS products

By Doug Miller, Milltech Marine Inc.

At Milltech Marine we sell a range of products mainly focused on the AIS market as well as products to enhance the AIS experience.

Often customers want to connect both a GPS and an AIS receiver to a navigation computer but they only have one serial port or USB port available. Many of our AIS receivers, including the Comar AIS-MULTI and the Smart Radio SR161 and SR162 receivers, support multiplexing an inbound GPS feed with the AIS data stream and then outputting a combined AIS and GPS data stream to another device such as a computer. This single serial data stream can then be passed to a computer or other display such as the AISWatchMate.

 
A description of how each product works follows:

• The Comar AIS-MULTI multiplexes an inbound GPS signal from the Garmin GPS 17HVS and provides a combined AIS and GPS signal to a computer and AISWatchMate. The AIS-MULTI also acts as a VHF antenna splitter for both the AIS-MULTI and a VHF radio.
• Garmin GPS 17HVS is used to provide GPS data to other marine devices – either directly (e.g. the DSC radio) or multiplexed in with the AIS sentences via the AIS-MULTI (e.g. to the AISWatchMate and navigation computer).
• AISWatchMate uses the combined AIS and GPS datastreams from the AIS-MULTI NMEA output port.
• Navigation computer uses the combined AIS and GPS datastreams from the AIS-MULTI via the built-in USB port.
• A DSC-enabled VHF Radio also gets GPS data from the Garmin GPS 17HVS.

The connections from the various devices are as follows:

• The signal out from the GPS 17HVS (white wire) is connected to the NMEA IN+ on the AIS-MULTI (red data wire) and the GPS input wire on a DSC radio (color depends on the model of radio).
• The NMEA OUT+ on the AIS-MULTI (yellow wire) is connected to the signal in on the AISWatchMate (green wire).
• The VHF antenna is connected to the AIS-MULTI and the antenna output from the AIS-MULTI is connected to the antenna input on the VHF radio.
• The USB interface from the AIS-MULTI is connected to the navigation PC.
• The various common grounds and NMEA negative signal wires are connected together.
• The positive 12vDC power leads for each device are connected to appropriate breakers leading to the battery.

More information on these products can be found on our products pages.