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Networking is an important technology in today's vehicles: Up to 100 electronic control units are interlinked through various communication protocols such as CAN, LIN, MOST, etc. As such communication protocols represent a “standard” component in vehicles which is assumed to provide a specified functionality regardless who the manufacturer is. Unfortunately 10 years of practical experience show that implementations of communication protocol specifications done by different manufacturers in most cases are not compliant a priori. Luckily experience of automotive OEMs together with their suppliers and silicon manufacturers have proven that conformance testing is a very effective means to avoid interoperability problems in mixed suppliers automotive systems. The following paper describes for LIN protocol the process of conformance test specification, conformance test suite implementation and the experiences gained while performing such tests.

Actually automotive industries is in a dilemma: Further customer satisfaction requires further features to be built into cars and this requires more electronics in cars. All this currently happens at a rapidly increasing pace and thus increasing networked cars electronic control systems complexity correspondingly. Networking obviously requires interoperable communication modules consisting of communication hardware and software. And here is the problem: As network protocols are specified mostly in natural languages such as English, no precise and non-ambiguous specification exists. As such implementers may understand the same specification differently. And as a result realizations of the same protocol may behave differently under certain operational conditions. As a consequence mixed suppliers control modules may not be able to communicate properly. Conformance testing is the solution to this problem.

Current in-vehicle electronics are based on networked modules. Knowing this and taking into account the rapidly increasing number of network nodes in cars, the proper functionality and interoperability of network interfaces produced by various manufacturers is an important pre-requisite in order to obtain a good quality system operation. One way to ensure good interoperability of network interfaces is to apply conformance tests. The following paper therefore outlines the specification of such conformance tests, as they are defined by ISO. Along with the specification of standard conformance tests a set of test extension is proposed checking the proper functionality of a network interface according to its register interface to the processor and its proper behavior in (random) stress situations - referred to as random or robustness tests. Finally an implementation of a tester performing the conformance tests is introduced.

Current vehicle electronic control units (ECUs) communicate with each other through networks. Easy integration of these ECUs into a system obviously requires well-standardized network interfaces and corresponding components, which meet the standard properly. One efficient means to ensure that communication interfaces are compliant with the standard is a conformance test standard. As CAN is a widely used communication standard interface in vehicles ISO has worked out a CAN conformance test standard, which is expected to be published as a Draft International Standard - DIS - by end of 1998. This article describes the developing standard, the implementation of a corresponding tester, and how conformance tests are performed. Further, more necessary extensions for more efficient conformance testing with better test coverage are discussed.

Networked systems inherently must be considered as highly complex systems. In order to guarantee high quality and highly efficient results while designing and applying networked systems the degree of complexity to be handled by the system designer must be decreased to an acceptable level. The methodology to achieve this goal is to hide details in software/hardware support drivers. The subsequently presented paper gives an overview on CAL = CAN Application Layer. CAL has been defined in Europe by industrial manufacturers of CAN networked controller systems. As the CAL features and characteristics are of generic type the gained results may be of interest for being considered in automotive applications. Furthermore CAL can be regarded as a generic higher layer for autobus protocols whether it is CAN, VAN, J1850, … Therefore the ideas presented in this paper may be a point of discussion for the design of a generic automotive communication layer.

Networking is a need for interlinking todays and future electronic modules into systems. Networked systems offer reduced wiring harness, more open system expandability and an additional degree of freedom for system optimization. On the other hand networked systems represent highly complex problems for the system designers and therefore require correspondingly powerful tools. Subsequently the characteristics of networking are described based on the example of the CAN-network-protocol. A set of requirements for needed tool support is derived from the inherent networked system characteristics. A set of CAN network development tools is described - Simulator, Emulator, Analyzer, handy NetTest, PcNet-interface - supporting the various needs in the different design phases. Finally some future activities are described depicting tools enhancement and integration. In addition research activities are mentioned focusing on definition and evaluation of higher protocol layers.