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SAE J2735-Draft-Rev18 [issued: 06-26-07]
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58 -
This is an SAE Motor Vehicle Council draft document of the DSRC committee, subject to change.
Used by: This entry is used directly by one other data structure in this standard, a DF called DF_Snapshot
Remarks: Revised in edition two of the standard to have a more logical tag value. The item tag (which
was made up of the ValueList before) is now made of the VehicleStatusDeviceTypeTag in this edition.
6.31 Data Frame: DF_Snapshot
Use: A report on one or more status elements in the vehicle which may have changed along with a set of
position and heading elements representing the location of the report. Each report can contain status
information on a number of defined vehicle devices.
ASN.1 Representation:
Snapshot ::= SEQUENCE {
thePosition FullPositionVector, -- data of the position and speed,
cntVSDTs INTEGER (0..31), -- a count of how many vehicle
-- status device type entires
-- will follow, 1 byte
deviceTypes SEQUENCE (SIZE(0..31)) OF
SnapshotItem, -- a seq of name-value pairs
-- which me may encode in the
-- style as other msgs, need to see
... -- # LOCAL_CONTENT
} -- Est size 2 bytes per payload item plus 10 for next position
XML Representation:
<xs:annotation>
<xs:documentation>
Est size 2 bytes per payload item plus 10 for next position
</xs:documentation>
</xs:annotation>
<xs:sequence>
<xs:element name="thePosition" type="FullPositionVector" />
<!-- data of the position and speed, -->
<xs:element name="cntVSDTs" >
<xs:simpleType>
<xs:restriction base="xs:unsignedByte">
<xs:maxInclusive value="31"/>
</xs:restriction>
</xs:simpleType>
</xs:element>
<!-- a count of how many vehicle
status device type entires
will follow, 1 byte -->
<xs:element name="deviceTypes" >
<xs:complexType>
<xs:sequence minOccurs="0" maxOccurs="31">
<xs:element name="deviceType" type="SnapshotItem" />
<!-- a seq of name-value pairs which me may encode in the style as
other msgs, need to see -->
</xs:sequence>
</xs:complexType>
</xs:element>
<xs:element name="localSnapshot" type="local:Snapshot" minOccurs="0"/>
</xs:sequence>
</xs:complexType>
Used by: This entry is directly used by the following 2 other data structures in this standard (record type,
descriptive name, ASN.1, and XML name (if present) of each):
DF
<XML>, and
MSG
In addition, this item may be used by data structures in other ITS standards.