If you think that your AIS transponder is not transmitting your position then this procedure might help you. The first step is to check if your AIS transponder is actually transmitting. If you are then sure that your AIS transponder is not transmitting then the next part explains you the factors to check.

 

1 – Check if your AIS is transmitting or not

 

With ProAIS2 or iAISTX/AIT5000 Web Interface

Using the proAIS2 configuration software or the iAISTX/AIT5000 web interface allows you to see if the GPS position is OK. You can monitor the AIS reception of other vessels. As well as ensure that there are no errors or alarms. However, if you are new to AIS, there is always that nagging doubt as to whether other vessels are seeing you.

 

 

Check with a local AIS Receiver/Transponder

The best test of a Class B transponder is to ask someone else in your marina, who has AIS, to check that they are receiving you on their system. If your vessel is stationary, then a transponder will only transmit every 3 minutes. This increases to every 30 seconds when your speed over the ground (SOG) is greater than 2 knots. Therefore, do allow some time for them to detect you. Also when they first receive your transmission, the only data they will see is your position, speed, course and MMSI number. It can take up to 6 minutes to receive your “Static Data” (boat name, call sign, vessel type, dimensions, etc.). This is normal and is the way the AIS system regulates the amount of data being transmitted.

 

 

Check with MarineTraffic, Vessel Finders, etc.

The other increasingly common method of testing an AIS transponder is to look on one of the online “live” AIS websites and the most popular of the free services is MarineTraffic.com

However, it is important for you to be aware of the limitations of these online sites. As a result, do not assume that you will always be picked up by them. Each of the different online services are only as good as their network of AIS receiving stations. In many cases enthusiasts/volunteers operate these. In some areas the coverage is great but there are definitely “holes” in coverage.

 

 

 

 

2 – Find out the reasons why your AIS is not transmitting

If you are now sure that your AIS transponder is not transmitting then you should follow the following steps.

You must use ProAIS2 for your AIT1500, AIT2000, AIT2500, AIT3000 or Nomad. However, for the iAISTX, iAISTX Plus or AIT5000, you must use the built-in web interface.

With proAIS2’s diagnostics tab or the iAISTX/AIT5000 web interface, you can check if an AIS transponder has an issue or not.

 

 

A- Check if your AIS receives a good GPS position.

Without a good GPS fix, an AIS transponder cannot transmit correctly your position. By going to the GPS Status tab in ProAIS2, you can see the GPS reception. If you have one of our AIS transponder with built-in GPS antenna, then you should consider installing a GPS booster (for more information, click here).

If you have an external GPS antenna then make sure that the connectors are correctly tight and also that the antenna is outside and has a clear view over the sky.

 

B- Check the VHF antenna

In the Diagnostics Tab in ProAIS2 or within the iAISTX/AIT5000 web interface, you can see the VSWR ratio. The VSWR ratio is explained in the FAQs. If your VSWR ratio is above 3, then you must check the VHF antenna connectors and the cable.

If possible, use another VHF aerial to check if the AIS transmits better.

 

C – Check that all the data have been entered

In the Configuration Tab in ProAIS2, you must make sure that all the boat details have been added (MMSI, VHF Call Sign, Name, Dimensions, etc.)

 

 

You can send us via email a screenshot of the ProAIS2 diagnostics tab or your iAISTX/AIT5000 web interface, we will then let you know whether the product works well or not.

 

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