There are two possibilities:
1. Your plotter or its software is too old.
It uses the message 1 for position update (there are 27 used messages within the AIS system) and 14. Message 14 is the SRM (Safety Related Message).
Within this there is the Navigational status: 15 is transmitted within Test-Mode by pressing the “TEST”-Button, 14 is for an active alarm by activating the unit.
Maybe your chart plotter is too old to show you the symbol of an “S.A.R.T.”. This is a red circle with a cross inside.
Please have a look at your ship list. Here you should see a MMSI number starting with 970 / 972. If yes, please try to contact the manufacturer of your plotter if there is an available update.
2. Your receiver could be overloaded. But what´s this?
Let us explain it in a different way. Somebody is screaming to you near your ears. So you are not able to understand him.
In this case the “ear” is the receiver and the noise comes from the transmitter. This means if you are to near to each other you cannot understand it by overloading.
If you go to a farer distance maybe >20 meters the receiver is able to understand the signal again.
In another way you also can twist the antenna around the transmitters housing to attenuade the radiated transmitting power. So you reduce the chance of overloading.
For the trials the easyRESCUE / easyONE also needs a GPS signal. So please go outside on deck or maybe the gangplank.
If somebody is falling into the water it takes round about 4-5 seconds to open the automatic life vest and to pull the person above the waterline.
Until the emergency transmitter has got the GPS fix it also can take 35 seconds up to 2min. Within very bad weather conditions and environment it also can take up to 5minutes.
So if a boot is driving 2 knows which is very slow the boat is moving 1.02 meters within one second. So under normal conditions the boat is moving 39 meters before the first signal from our unit and this distance is far enough that
all receivers can get this. So you don´t have to be worried about that “overloading”.