National Instruments 372139B-01 Automobile User Manual


 
Chapter 1 Introduction
Automotive Diagnostic Command Set User Manual 1-4 ni.com
Measurements
Use the ReadDataByLocal/CommonIdentifier services to access ECU data
in a way similar to a DAQ list. A Local/CommonIdentifier describes a list
of ECU quantities that are then transferred from the ECU to the tester. The
transfer can be either single value or periodic, with a slow, medium, or fast
transfer rate. The transfer rates are manufacturer specific; you can use the
SetDataRates service to set them, but this setting is manufacturer specific.
Note The Automotive Diagnostic Command Set supports single-point measurements.
Diagnostic Trouble Codes
A major diagnostic feature is the readout of Diagnostic Trouble Codes
(DTCs). KWP2000 defines several services that access DTCs based on
their group or status.
Input/Output Control
KWP2000 defines services to modify internal or external ECU signals. One
example is redirecting ECU sensor inputs to stimulated signals. The control
parameters of these commands are manufacturer specific and not defined
in the standard.
Remote Activation of a Routine
These services are similar to the ActionService and DiagService
functions of CCP. You can invoke an ECU internal routine identified by a
Local/CommonIdentifier or a memory address. Contrary to the CCP case,
execution of this routine can be asynchronous; that is, there are separate
Start, Stop, and RequestResult services.
The control parameters of these commands are manufacturer specific and
not defined in the standard.
External References
For more information about the KWP2000 Standard, refer to the
ISO 14230-3 standard.