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SAE J2735-Draft-Rev18 [issued: 06-26-07]
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207 -
This is an SAE Motor Vehicle Council draft document of the DSRC committee, subject to change.
DE_VehicleHeight
Yes (3 Hz)
Yes (3 Hz)
DE_VehicleLength
Yes (3 Hz)
Yes (3 Hz)
DE_VehicleMass
Yes (3 Hz)
Yes (3 Hz)
DE_VehicleType
Yes (3 Hz)
Yes (3 Hz)
DE_VehicleWidth
Yes (3 Hz)
Yes (3 Hz)
DE_VerticalAccelerationThreshold
DE_VerticalAcceleration
DE_WiperRate
DE_WiperStatus
DE_YawRatePrecision
DE_YawRate
Ad Hoc Data
AHDE_CAWMap
Yes (10 Hz)
Yes (10 Hz)
Table: Data Frames, Data Elements with Identifier, and Tagged Data Elements as used by the two applications in this
example.
3.2
Message Structure
The MD combines the different data frames and data elements required by the two
applications into the minimum size message. For this example, the MD uses the
following logic to perform compose the message:
Duplicate data frames and data elements requested by both applications are not
repeated.
If a data element requested by one application is also contained within a data
frame requested by another application, it is only included as part of the data
frame.
Data frames and data elements are transmitted only at their maximum required
frequencies. In fact, in this example some data frames/elements are sent less
frequently then others and they are not included in each message.
Since the applications have registered data at three different frequencies, the MD will use
the MSG_AlaCarte message defined by this Standard to construct three different ad hoc
messages called Msg10Hz, Msg5Hz and Msg3Hz. Other message types may also e used.
The contents are described below and are built using the following pieces of information
from the standard:
Standard data tags StdTagList are 1 byte long as defined by this Standard in the
section defining the data concept DE_StdTagList
Standard data frame and element lengths in bytes as defined in each data frame
definition (clause 6).
Ad hoc data tags from the TwoByteTagList are 2 bytes long as defined by this
Standard in section 4.3
Ad hoc data length and tag value may defined by the application and notified to
the MD as described in this annex.
Ad Hoc data tags defined by the CAW application that are outside this Standard.
In particular, a the CAW application defines one ad hoc data element called