User's Manual

Configuration using proAtoN
Page 35
● MMSI - the MMSI number associated with the ‘real’ AtoN. Typically the MMSI number for a ‘real’ AtoN
station follows the format 99MID1XXX where MID is the appropriate national MID and XXX is a
number unique to this station.
● Name - the name of the AtoN station as broadcast to other AIS users. Up to 34 characters are
available for the name.
● Type of AtoN - select from a list of possible types of AtoN. The types are as defined by IALA in IALA
A-126.
● Type of EPFS - Select the type of EPFS (Electronic Position Fixing System) used by the transceiver.
Note this selection does not affect the hardware configuration, only the contents of the ‘Type of EPFS’
field in transmitted AtoN position reports. The transceiver is equipped with a GPS module by default.
Alternatively for a fixed or shore based transceiver a surveyed position type can be selected. Note
that when the surveyed position is selected the surveyed position is broadcast to other AIS users and
GNSS position information is ignored.
● Nominal position - Enter the nominal or charted position of the AtoN. This is the position transmitted
to other AIS users for a fixed AtoN when the ‘Surveyed’ EPFS type is selected. For all other
configurations this position is used to perform ‘off position’ calculations only; the actual GNSS position
is broadcast to other users.
○ The application can average the current GNSS position over 5 minutes and use this value for the
nominal position. Click the ‘Get GNSS position’ button to the right of the latitude and longitude
fields to begin this process.
○ The position accuracy can only be entered when the type of EPFS is set to ‘Surveyed’. The
accuracy should be set in accordance with the accuracy of the surveyed position.
● Off position alternate message enable - the current GNSS position is compared to the nominal
position according to the algorithm defined in IALA A-126 Annex A, Example 1. The off position
threshold distance is specified in metres. If the transceiver determines that it is ‘off position’ then the
alternate reporting schedule for message #21 (index 2) is enabled. For example, the alternate
reporting schedule could be configured to decrease the reporting interval if the AtoN has drifted off
position. The off position flag in message #21 is set when off position regardless of this setting.
The transceiver off position algorithm is always operational and compares the current GNSS position
to the nominal position of the transceiver.
● MMSI for addressed messages - this is the destination MMSI used for all addressed message types
generated by the transceiver. This is usually the MMSI of a shore station collecting status information
from the transceiver. It is also possible to enable the acknowledgement of received binary messages
(via message #7 or #13).
● Dimensions - the dimensions of the AtoN should be entered to the nearest metre. Guidance on the
appropriate configuration of dimensions for various types of AtoN can be found in IALA A-126.
● Radio channels - Selection of alternative radio channels for AIS transmission and reception is
possible, however in most cases the default channels (AIS1 and AIS2) should be used.
● Transmitter power level - The transmitter power level for the transceiver can be selected as 1W, 2W,
5W or 12.5W. The default value of 12.5W is appropriate for most scenarios.
It is essential that valid nominal position is entered and that a reasonable off position
threshold is entered. If the default nominal is left unchanged or an incorrect position is
entered then the transceiver will always be ‘off position’ resulting in the GNSS receiver being
permanently enabled. This will lead to significantly increased power consumption and the ‘off
position’ flag in the Aids to Navigation report will be set.
!