[Dcm] Vehicle Diagnostic Communication Part 69 [Simulation 8]

[Dcm] Vehicle Diagnostic Communication Part 69 [Simulation 8] 車両診断通信
[Dcm] Vehicle Diagnostic Communication Part 69 [Simulation 8]

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Explanation of AUTOSAR-Dcm configuration.
In this article, the role of Dsd, class diagrams, etc. will be explained.

Role of AUTOSAR-Dcm Dsd

In this article, I will begin to explain Dsd, one of the sub-modules of Dcm.

Dsd stands for Diagnostic Service Dispatcher, and it is used to determine which service the message is actually for based on the received message.
Since the message is determined by Dsl, it determines which service the message actually belongs to.
The first byte of the message is the service ID, so the determination itself is not difficult.

Well, it is the easiest of the three submodules, but whether it is easy or not is another matter.
It is not so important, but Dsd is also responsible for determining the corresponding security level and session status for each service.
To explain in a little detail, the Dsd checks if the corresponding service supports the current security level and session.

This means that the relevant parameters will be included in the Dsd configuration.
Since the relevant parameters are under the jurisdiction of Dsp, not Dsd, it is strictly a reference only.
The security level and sessions held by Dsp from each service will be referenced.

AUTOSAR-Dcm Dsd configuration structure

If you could take a look at the class diagram, you’d see how simple it is.

Dsd class diagram,Dcm_DsdType,Dcm_DsdServiceTableType,Dcm_DsdServiceType,Dcm_DspSecurityRowType,Dcm_DspSessionRowType,Enable/disable status of various services,Security status associated with the service,Session state associated with the service

AUTOSAR-Dcm Dsdコンフィグレーション構造の簡単な説明

It’s simple enough that you might recognize it when you see it, but here is a brief explanation.

  • Dcm_DsdServiceTableType defines the service set.
  • Dcm_DsdServiceType defines the actual service to be supported.
  • Each security level and session is associated with it, and this is the security level and session supported by the service in question.


  • Dsd is a sub-module whose purpose is to distribute to each service.
    • At the same time, it also determines the security level and sessions to be supported.
  • For the above purposes, it has the following configuration parameters
    • Existing service definition.
    • Support service definition.
    • Definition of the security level and sessions that the service can support.

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