![[Dcm] Vehicle Diagnostic Communication Part 63 [Simulation 2]](https://www.simulationroom999.com/blog/wp-content/uploads/2022/12/01_eyecatch-25.png)
Click here for back issues.
https://www.simulationroom999.com/blog/diagnostic-communication-en-back-issue/
Introduction.
In this article, I will explain the interface of AUTOSAR-Dcm.
Specification of AUTOSAR-Dcm
As with AUTOSAR-CanTp, we should first understand the AUTOSAR-Dcm interface.
Since OpenSAR is r3.x, you should read the AUTOSAR-Dcm specification for r3.3.
Currently, old versions of the AUTOSAR classic platform can no longer be downloaded. Therefore, it is temporarily placed here.
Interfaces for AUTOSAR-Dcm
I have extracted the necessary interfaces.
The following five are them.
- Dcm_ProvideRxBuffer
- Dcm_RxIndication
- PduR_DcmTransmit
- Dcm_TxConfirmation
- Dcm_MainFunction
You probably thought it was less than you thought.
These are only interfaces for communication.
The problem with AUTOSAR-Dcm is the number of configuration parameters.
Explanation of the AUTOSAR-Dcm interface
I will explain the previous interface as follows.
| Function | Description |
|---|---|
| Dcm_ProvideRxBuffer | Request for buffer to be used by the transport layer when FirstFrame or SingleFrame is received. |
| Dcm_RxIndication | Message reception completion notification. (After receiving SingleFrame/ after receiving the last consecutive frame) |
| PduR_DcmTransmit | Request for transmission from the Dcm to the transport layer; in the case of NRC$78, multiple transmission requests are generated. |
| Dcm_TxConfirmation | Message transmission completion notification. |
| Dcm_MainFunction | Main loop. Must be called periodically. |
It looks surprisingly normal in this way.
This is because the pure protocol part has been absorbed by CanTp.
However, the explanation of PduR_DcmTransmit is a bit fuzzy.
You can assume that this is simply for NRC$78 handrigs.
AUSOTAR-CanTp only supports sending and receiving messages in accordance with ISO 15765-2.
NRC$78 is designed in accordance with AUTOSAR-Dcm, or ISO14229-1.
Therefore, it is required to be handled on the AUTOSAR-Dcm side, which is higher than AUSOTAR-CanTp.
Well, NRC$78 is a special response message, but it is just a SingleFrame as AUSOTAR-CanTp or ISO15765-2.
Therefore, multiple responses are generated for ISO14229-1 reasons, which is how ISO15765-2 behaves from its standpoint.
In other words, it is the division of responsibility due to the layered structure.
You probably wished I had explained this in a diagram….
I’ll try to have one ready by next article….
Conclusion
- Check AUTOSAR-Dcm specification (r3.3).
- Check AUTOSAR-Dcm interface.
- NRC$78 is just SingleFrame as AUTOSAR-CanTp.
Click here for back issues.
コメント