National Instruments 372139B-01 Automobile User Manual


 
Chapter 6 Automotive Diagnostic Command Set API for C
Automotive Diagnostic Command Set User Manual 6-82 ni.com
ndUDSDiagnosticSessionControl
Purpose
Executes the UDS DiagnosticSessionControl service. The ECU is set up in a specific
diagnostic mode.
Format
long ndUDSDiagnosticSessionControl(
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. The usual values are:
01: defaultSession
02: ECUProgrammingSession
03: ECUExtendedDiagnosticSession
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.