With the increasing complexity of vehicle electronics and the embedding of numerous vehicle functions into the ECU software, there is a parallel increase in the number of OBD relevant software modules. Currently, the OBD relevant software modules constitute around 70% of the ECU software with a tendency to expand even further. For this reason, the comprehensive and systematic validation of all available diagnostic services as well as all possible valid and invalid combinations thereof has become a very complex, time-consuming task involving many resources.
Softing’s OTX Studio, a universal and ISO 13209 compliant tool, provides a number of functions including the creation of tests for the comprehensive and automated validation of ECU diagnostic services with an optional Test Case Editor. Such comprehensive validation is typically required for acceptance and regression tests. For this purpose all available diagnostic services along with their various parameterizations have to be systematically tested and documented. Tests created with the Test Case Editor are based on pre-configured OTX scripts, which are parametrized accordingly, and used for the creation of automated, OTX script based validation tests.
The validation tests based on such OTX sequences and supported by the Test Case Editor enable the fast and convenient creation of complete ODX and OTX based validation sequences. The user can implement the typical test blocks which he can simply drag & drop onto the test documentation template which, at the same time, is a composition of the required validation test steps.
Therefore, the user can implement the Test Case Editor to very easily create test cases which perform the complete validation of an ECU. The tests are not only limited to the validation of single diagnostic services. They can be extended to the validation of complete diagnostic groups as well as the validation of communication behavior. Within these tests the user can create further tests which validate the positive and negative responses of an ECU. Such tests can include the validation of valid or invalid diagnostic service requests, as well as test iteration through the complete value ranges e.g. for text tables, complex and extended data types.
In the area of communication behavior validation, the user can create test cases for monitoring CAN communication, the communication between the test environment and the device under test (DUT), as well as for verifying the communication timing parameters.
Furthermore it is possible to filter CAN frames using the message ID or other attributes such as, for example, the first or consecutive frames in the diagnostic communication protocol.
For good test coverage of the diagnostic services, one of the major requirements is that not only positive ECU responses are validated but also the negative and invalid ones.
For this purpose, the Test Case Editor provides an additional feature which allows the checking of responses with special patterns . With this feature, the user can choose whether to check single bytes, regardless of their position in the communication sequences, or alternatively partial or complete diagnostic sequences.
To ensure that the integrity of an ECU remains intact even if it is flooded with invalid diagnostic sequences, the Test Case Editor enables the automatic creation of suitable test cases for this specific case.
With this kind of validation test, the user can check how the ECU responds or does not respond to the invalid diagnostic service requests. The tests cover not only invalid or malformed diagnostic services but also invalid parameter values with valid diagnostic services.
To fine-tune the validation tests, the user can use loops and time pauses, perform raw CAN bus communication (e.g. execute custom hex services) and can integrate other, test case specific OTX scripts.
A validation test created with the Test Case Editor is compiled into OTX script with OTX Studio’s OTX compiler and executed by the OTX runtime (OTX RT). In addition to the OTX runtime integrated in OTX Studio, Softing also offers stand-alone OTX runtimes for the operating systems Android, iOS, Linux and Windows.
The created validation tests can therefore be reused in different test environments and different use cases.
OTX provides the perfect solution for a comprehensive and systematic validation of all diagnostic services available on an ECU as well as their valid and invalid combinations. With OTX Studio and the optional Test Case Editor, the user can simply and efficiently create very comprehensive validation tests and reuse these in different use cases and test environments.