Purpose

Executes the WWH-OBD ReadDataByIdentifier service to retrieve the valid DID values for this service.

Format 

        long ndWWHOBDRequestSupportedDIDs (
       TD1 *diagRef,
       unsigned short DID,
       unsigned char DIDsOut[],
       long *len,
       LVBoolean *success);

Input

diagRef

Specifies the diagnostic session handle, obtained from ndOpenDiagnosticOnCANFD and passed to subsequent diagnostic functions. Normally, it is not necessary to manually manipulate the elements of this struct.

DID

Specifies the diagnostic data identifier for this service. The following values are valid and can be obtained through an enum control:

0: PID: parameter identifier
1: MID: monitor identifier
2: ITID: info type identifier

Output

DIDsOut

Returns an array of valid DIDs.

len

On input, len must contain the DIDsOut array length. On return, it contains the number of valid elements in the DIDsOut array.

success

Indicates successful receipt of a positive response message for this diagnostic service.

Return Value

The return value indicates the function call status as a signed 32-bit integer. Zero means the function executed successfully. A negative value specifies an error, which means the function did not perform the expected behavior. A positive value specifies a warning, which means the function performed as expected, but a condition arose that may require attention.

Use the ndStatusToString function to obtain a descriptive string for the return value.

Description

The WWH-OBD ReadDataByIdentifier service is based on the UDS ReadDataByIdentifier service (ISO 14229-1).