National Instruments CAN 372139B-01 - Manual (Page 195)

Chapter 6 Automotive Diagnostic Command Set API for C
© National Instruments Corporation 6-31 Automotive Diagnostic Command Set User Manual
Status Code Use
The application code should check the status returned from every Automotive Diagnostic
Command Set function. If an error is detected, close all Automotive Diagnostic Command Set
handles and exit the application. If a warning is detected, you can display a message for
debugging purposes or simply ignore the warning.
The following code shows an example of handling Automotive Diagnostic Command Set
status during application debugging.
Status = ndOpenDiagnostic ("CAN0", 500000, 0, 0x7E0, 0x7E8,
&MyDiagHandle);
PrintStat (status, "ndOpenDiagnostic");
where the function PrintStat has been defined at the top of the program as:
void PrintStat(mcTypeStatus status, char *source)
{
char statusString[1024];
long len = sizeof(statusString);
if (status != 0)
{
ndStatusToString(status, statusString, &len);
printf("\n%s\nSource = %s\n", statusString, source);
if (status < 0)
{
ndCloseDiagnostic(&MyDiagHandle);
exit(1);
}
}
}
Status Code Definition
Negative Error—Function did not perform the expected behavior.
Positive Warning—Function performed as expected, but a condition arose that
may require attention.
Zero Success—Function completed successfully.