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SAE J2735-Draft-Rev15 [issued: 01-30-07]
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This is an SAE Motor Vehicle Council draft document of the DSRC committee, subject to change.
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.
6.17 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:complexType name="Snapshot" >
      <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 
<ASN> <XML>, and
MSG
In addition, this item may be used by data structures in other ITS standards.