PEAK-System Forum

I call service ReadDataByPeriodicIdentifier at medium rate, wanting to read 0xF200 and 0xF204.

My code:

string TC_UDS_266()
{
    string s;
    TPUDSStatus r;
    unique_ptr<PUDSClass> pcan(new PUDSClass());

    if (pcan->openDevice(PUDS_USBBUS1, PUDS_BAUD_250K) != PUDS_ERROR_OK)
    {
        cout << "UDS-266: failed to initialize" << endl;
        return "UDS-266: FAILED";
    }

    cout << "initialized" << endl;

    TPUDSMsg requestConfirmation;
    TPUDSMsg response;
    memset(&requestConfirmation, 0, sizeof(TPUDSMsg));
    memset(&response, 0, sizeof(TPUDSMsg));

    WORD bufferLength = 2;
    BYTE buffer[bufferLength] = {};
    buffer[0] = '00';
    buffer[1] = '04';

    r = pcan->SvcReadDataByPeriodicIdentifier(&pcan->request, 0x01, buffer, bufferLength);
    if (r == PUDS_ERROR_OK)
        r = pcan->WaitForService(&response, &requestConfirmation);
    if (r == PUDS_ERROR_OK)
    {
        cout << "Response was received" << endl;
        //cout << "SID: " << response.DATA.POSITIVE.SI << endl;

        s = "UDS-266: PASSED";
    }
    else
    {
        cout << "An error occured" << endl;
        s = "UDS-266: FAILED";
    }

    return s;
}

Problem is, when I'm watching data on other device, i see these 2 messages:
Send: [04 2A 01 30 34]
Received: [03 7F 2A 7F]

The response is ok, since this service is no allowed in default session, but I can't understand why it sends "... 30 34]" and not "...00 04]". Even if I set buffer (PIDs) to ["A0", "B4"], it still sends "30" and "34".

Dear Valev,

The following code is incorrect, as you are confusing an integer hex value with a char value (char '04' is 0x34 in ascii):

Code: Select all

    WORD bufferLength = 2;
    BYTE buffer[bufferLength] = {};
    buffer[0] = '00';
    buffer[1] = '04';

Also your code should not compile without a const value in front of "WORD bufferLength = 2;"

Here is the corrected version:

Code: Select all

    const WORD bufferLength = 2;
    BYTE buffer[bufferLength] = {};
    buffer[0] = 0x00;
    buffer[1] = 0x04;

Thank you, easy fix for more experienced programmers.

Also your code should not compile without a const value in front of "WORD bufferLength = 2;"

I have no problems even if I don't have "const" there. In your API user manual, in example, there also is no "const" there. Are you sure it's needed?

It may depends on your compiler but on VS2019 it doesn't.

I see, I have GCC, no problems here. Will keep in might if anything goes wrong. Thank you again for the help.

PEAK-System Forum

Wrong PIDs in ReadDataByPeriodicIdentifier

Wrong PIDs in ReadDataByPeriodicIdentifier

Re: Wrong PIDs in ReadDataByPeriodicIdentifier

Re: Wrong PIDs in ReadDataByPeriodicIdentifier

Re: Wrong PIDs in ReadDataByPeriodicIdentifier

Re: Wrong PIDs in ReadDataByPeriodicIdentifier