PAS 61162-101:2003 pdf download Maritime navigation and radiocommunication equipment and systems — Digital interfaces — Part 101: Single talker and multiple listeners — Modified sentences and requirements for IEC 61162-1
Scope
This PAS document for lEC 61162-1 contains additional requirements for existing sentencesand details additions to the existing format which have been found desirable in the light otfield experience.
This is the second PAS document to be developed for the lEC 61162-1, reference should bemade to IEC/PAS 61162-100 which covers the requirements of the universal shipborneAutomatic Identification System (AlS).
2Normative references
The following referenced documents are indispensable for the application of this documentFor dated references, only the edition cited applies. For undated references, the latest editionof the referenced document (including any amendments) applies.
Additions to this list are concerned solely with the new AlS and IEC/PAS 61162-100 should bereferred to for details.
3 Definitions
3.1
Parametric sentences(Reference IEC 61162-1 Section 5 :Data format protocol)
These sentences start with the “$” delimiter, and represent the majority of approvedsentences defined by this standard. This sentence structure, with delimited and defined datafields, is the preferred method for conveying information.
The basic rules for parametric sentence structures are:
a) The sentence begins with the “$” delimiter.
b) Only approved sentence formatters are allowed. Formatters used by special-purposeencapsulation sentences cannot be reused. See Annex C, tables C.1 and C.2.
c) Only valid characters are allowed. See Annex B, tables B.1 and B.2
d) Only approved field types are allowed. See Annex A, table A.1.
e) Data fields (parameters) are individually delimited, and their content is identified and oftendescribedin detail by this standard.
f) Encapsulated non-delimited data fields are NOT ALLOWED
3.2
Encapsulation sentences(Reference IEC 61162-1 these are new sentences : see note below)
There follows a brief description of the Encapsulation sentence. Note that a full description isto be found in the lEC/PAS 61162-100 for the universal shipborne Automatic ldentificationSystem(AIS).
These sentences start with the “!” delimiter. The function of this special-purpose sentencestructure is to provide a means to convey information, when the specific data content isunknown or greater information bandwidth is needed.This is similar to a modem thattransfers information without knowing how the information is to be decoded or interpreted.The basic rules for encapsulation sentence structures are:a) The sentence begins with the “!” delimiter.
b) Only approved sentence formatters are allowed.Formatters used by conventionalparametric sentences can not be reused.
c) Only valid characters are allowed.
d) Only approved field types are allowed)
e) Only Six bit coding may be used to create encapsulated data fields.
f) Encapsulated data fields may consist of any number of parameters, and their content isnot identified or described by this standard.
gThe sentence must be defined with one encapsulated data field and any number ofparametric data fields separated by the “” data field delimiter. The encapsulated datafield shall always be the second to last data field in the sentence, not counting thechecksum fieldh)
h)The sentence contains a“Total Number Of Sentences” field.The sentence contains a“Sentence Number” field.
j) The sentence contains a “Sequential Message ldentifier” field.klThe sentence contains a “Fill Bits” field immediately following the encapsulated data fieldThe Fill Bits field shall always be the last data field in the sentence, not counting thechecksum field.
NOTE This method of conveying information is to be used only when absolutely necessary, and will only beconsidered when one or both of two conditions are true, and when there is no alternative.
Condition 1: The data parameters are unknown by devices having to convey the information. For example, theABM and BBM sentences meet this condition, because the content is not known to the Universal Automaticldentification System (AIS) transponder.
Condition 2: When information requires a significantly higher data rate than can be achieved by the lEC 61162-1(4 800 baud) and IEC 61162-2 (38 400 baud) standards utilising parametric sentences.By encapsulating a large amount of information, the number of overhead characters, such as “” field delimiters canbe reduced, resulting in higher data transfer rates. t is very unusual for this second condition to be fulfiled. As anexample. a UAlS transponder has a data rate capability of 4 500 messages per minute, and satisfies this condition.resulting in the VDM and VDO sentences.