AUTOSAR configuaration - DCM module

Question

I am stuck at a point where I am configuring the DCM module and the current parameter I am trying to configure DcmTimStrP2AdjustServer,

The requirement is P2CAN_SERVER_MAX = 25ms; P2STARCAN_SERVER_MAX = 5000ms;

Is DcmDspSessionP2ServerMax the same as P2CAN_SERVER_MAX? and if it is the same What is the need for DcmTimStrP2AdjustServer and how do I find the best value for DcmTimStrP2AdjustServer.(The values all should be a multiple of DcmTaskTime which I find to be logical).

DcmTaskTime = 5ms;

I am following Autosar 4.0.3, using ETAS tool for configuring the parameters.

score 2 · Answer 1 · answered Mar 09 '17 at 02:01

2

To fulfill your requirement, you need to configure respectively DcmDspSessionP2ServerMax & DcmDspSessionP2StarServerMax for each session control in the DcmDspSessionRows at Dcm/DcmConfigSet/DcmDsp/DcmDspSession/. i.e.

DcmDspSessionP2ServerMax 25
DcmDspSessionP2StarServerMax 5000

There is no DcmTimStrP2AdjustServer, but I guess you're referring to DcmTimStrP2ServerAdjust instead. DcmTimStrP2ServerAdjust & DcmTimStrP2StarServerAdjust should be configured to a multiple of your DcmTaskTime (5ms in your case, so i.e. 5ms, 10ms, 15, ms, ... is applicable) and are used to safeguard that the response is available on the bus before triggering the P2 or P2* timeouts. In your case you may want to set these values to the same values as in the DcmDspSessionRows if there is no other specification given, because the chosen timeout values there are already multiples of your DcmTaskTime:

DcmTimStrP2ServerAdjust  25
DcmTimStrP2StarServerAdjust 5000

answered Mar 09 '17 at 02:01

Constantin

8,721
13
75
126

But what I had configured was DcmDspSessionP2ServerMax 35 and DcmTimStrP2ServerAdjust 10 so that servermax-serveradjust = 25. Is this correct or Am I missing something again? – Sivaramakrishna Shriraam Mar 13 '17 at 15:56
@SivaramakrishnaShriraam How did you came up with the formula `DcmDspSessionP2ServerMax - DcmTimStrP2ServerAdjust = P2CAN_SERVER_MAX`? That doesn't look right to me, you want to have the same timeout value except if `DcmDspSessionP2ServerMax` is not a multiple of your `DcmTaskTime`. The default value for `DcmTimStrP2ServerAdjust` is the same as `DcmDspSessionP2ServerMax`. – Constantin Mar 14 '17 at 02:44
I could not configure the DcmTimStrP2ServerAdjust to 25, it(ETAS tool) said that the DcmDspSessionP2ServeMax - DcmTimStrP2ServerAdjust > DcmTaskTime. – Sivaramakrishna Shriraam Mar 16 '17 at 09:16

score 1 · Accepted Answer · answered Jul 18 '17 at 01:34

The adjust value is an internal value, in order to adjust the delay between the Dcm Transmit Request and the message being actually on the Bus.

The definition of P2ServerMax and P2*ServerMax and their corresponding Adjust values is the same:

This parameter is used to guarantee that the diagnostic response is available on the bus before reaching P2 by adjusting the current DcmDspSessionP2ServerMax. This parameter mainly represents the software architecture dependent communication delay between the time the transmission is initiated by DCM and the time when the message is actually transmitted to the bus

AUTOSAR configuaration - DCM module

2 Answers2