National Instruments CAN 372139B-01 - Manual (Page 228)

Chapter 6 Automotive Diagnostic Command Set API for C
Automotive Diagnostic Command Set User Manual 6-64 ni.com
ndStartDiagnosticSession
Purpose
Executes the StartDiagnosticSession service. The ECU is set up in a specific diagnostic mode.
Format
long ndStartDiagnosticSession(
TD1 *diagRef,
unsigned char mode,
LVBoolean *success);
Input
diagRef
Specifies the diagnostic session handle, obtained from ndOpenDiagnostic and passed
to subsequent diagnostic functions. Normally, it is not necessary to manually manipulate
the elements of this struct.
mode
Indicates the diagnostic mode into which the ECU is brought. The values are application
specific.
Output
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.