National Instruments CAN 372139B-01 - Manual (Page 224)

Chapter 6 Automotive Diagnostic Command Set API for C
Automotive Diagnostic Command Set User Manual 6-60 ni.com
ndRequestSeed
Purpose
Executes the SecurityAccess service to retrieve a seed from the ECU.
Format
long ndRequestSeed(
TD1 *diagRef,
unsigned char accessMode,
unsigned char seedOut[],
long *len,
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.
accessMode
Indicates the security level to be granted. The values are application specific. This is an
odd number, usually 1.
Output
seedOut
Returns the seed from the ECU.
len
On input, len must contain the seedOut array length. On return, it contains the number
of valid data bytes in the seedOut 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.