# Commission Implementing Regulation (EU) 2019/838 of 20 February 2019 on technical specifications for vessel tracking and tracing systems and repealing Regulation (EC) No 415/2007, Division 5.3: Extension of Message 21 with inland-specific type of AtoN

Extent: E+W+S+N.I.

The parameter field ‘AtoN status’ is used for the extension of Message 21 with inland-specific type of AtoN.
The parameter field ‘AtoN status’ is organised in eight pages, of which page ID 0 is 0 = default, page ID 1 to 3 is for regional use and page ID 4 to 7 is for international use. The first three bits of the AtoN status filed defines the page ID, the remaining 5 bits contains the information of the page.
The region, in which page ID 1 to 3 is applicable is defined by the Maritime Identification Digits within the MMSI of the transmitting AIS AtoN station. Thus the bit coding of the 5 information bits in the AtoN status field is only applicable in this specific region.
As regards Union inland waterways page ID 1 of the AtoN status field contains the list of inland-specific type of AtoN used.
To set an inland-specific type of AtoN in Message 21 two steps have to be made. First the parameter ‘Type of aids-to-navigation’ in Message 21 needs to be set to ‘0 = Default, type of AtoN not specified’. Second, the parameter ‘AIS status’ needs to be set to page ID 1 and the appropriate code of the Inland-specific type of AtoN, as follows:
Msg 21 — AtoN status:
Bits:
LSB
coding:
Page ID
type of AtoN (0-31)

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Source: https://www.legislation.gov.uk/eur/2019/838/annex/division/5/division/5.3 (the official version)
Page: https://openlegislation.uk/eu-regulation-2019-838/annex/division-5/division-5.3
Contains public sector information licensed under the Open Government Licence v3.0. Source: legislation.gov.uk, The National Archives.