You can make a reasonable test of the output of the AIS receiver by monitoring the NMEA-0183 data lines using a standard serial
port interface and terminal software
. For the Standard-Horizon GX2200 the AIS data is being sent:
TALKER A = Yellow
TALKER B = White
If you have an RS-422 serial
interface on a computer, you should be able to interface the computer to the radio. Then open a terminal application and read the data from the radio. You should see output from the radio when there are AIS targets in range. The mini chartplotter
in the radio will let you know when you have a target in range. You will see data containing sentences beginning with VDM. A typical message will look something like this:
Even if there are no actual vessels in range, if you are near a USCG RESCUE
21 site, and that site is also hosting a N-AIS transponder, the site will be sending an AIS BASE STATION Message all the time, giving you a test signal to use. Also, if there are any AIS Aid-to-Navigation signals in your area, they are also transmitted all the time. I am in SE Michigan, and there are dozens of AIS AtoN signals being sent continually, so even if there are no vessels, the AIS channel has a lot of traffic on it. And these signals are transmitted from sites with 20 to 40 mile radio horizons, so you can hear them a long way away.
Once you verify that you are seeing NMEA-0183 output from the radio on the YELLOW/WHITE pair, you can move on to testing the Actisense Gateway device.
There is no simple way to test the functionality of the Actisense NMEA gateway device, unless you happen to have some fancy NMEA-2000 test gear
at your disposal. But you can rudimentarily test it by assuming it works and looking for some sign on the downstream chartplotter that it is plotting targets. However, that is another problem: does your chartplotter know about AIS and does it plot targets.
I have no familiarity with the particular B&G chartplotter you have, and I would not say that to assume it can show AIS targets is a sure bet. However, I think B&G is part of Navico
, and Navico
chartplotters have surprisingly good outcomes with plotting AIS targets. For example, I was astounded to find that my rather old Lowrance HDS first-generation chartplotter, whose firmware has not been updated in several years, was able to plot AIS Aid-to-Navigation (AtoN) signals, which are just coming into use. But it does not plot AIS base stations. (So you can't use the AIS Base Station signal as a test and be completely confident the plotter will show it.) But on that basis, your B&G chartplotter is probably cable of plotting AIS targets.
Well, sorry to ramble here, and not give you much real help--but if you verify the radio is putting out VDM sentences, then at the least you have eliminated the radio as the culprit in your lack of success.
For a bit more detail about the radio and AIS sentences, you might find this article useful:
Standard-Horizon: GX2200 AIS - Moderated Discussion Areas