One of the major tasks of ECU development is the calibration and test of control strategies, i.e. tuning of parameters and the recording of internal variables during the runtime of the ECU. These tasks can be done via various busses, bus protocols or proprietary plug-on devices between the ECU and the calibration system. Those interfaces are technology-dependent and vendor-specific. In order to provide uniform access to an ECU, calibration tools typically have an MC-server that other tools can use to connect to an ECU without having to deal with different interface technologies. The main objective of the ASAM MCD-3 MC standard is to specify the functions of an MC-server and to provide a remote control interface for client applications to the MC-server via an object-oriented API. The functions of an MC-server are primarily to provide measurement and calibration services to clients. The standard allows that any client application, such as test automation systems or automated calibration systems, can connect via the MC-server to an ECU and carry out typical measurement and calibration tasks. Several client applications can be connected to one MC-server and have access to one ECU in parallel.
To be able to access data on an ECU, the MC-server reads an A2L data description file (according to ASAM MCD-2 MC), which contains a description of available calibration parameters (CHARACTERISTICS) and measurement variables (MEASUREMENTS). The MC-server then makes services available to access this data. Methods for read- and write-access to the calibration parameters of various types such as scalars, arrays, strings and look-up tables can be used. Measurement access methods are available via Collector, Watcher and Recorder services. The Collector acquires the values of measurement variables or calibration parameters with a common rate over a defined period of time (continuous data acquisition) and sends the data to the client applications at the same time. The Recorder is used to manage high bandwidth measurements, when synchronous data transfer to the client is not possible. The Recorder stores the data locally and makes it available to clients at a later time. A Watcher is a service which continuously monitors measurement variables or calibration parameters and triggers events if a predefined condition is met. Multiple Watchers can be defined to monitor multiple objects at the same time. The Watcher may be used to start and stop Collectors or Recorders.
The standard is used for calibration and measurement purposes in development, testing and production of ECUs. ASAM MCD-3 MC currently coexists with the older ASAM ASAP3 standard, which is dependent on specific interfaces (RS232, Ethernet) and is still widely used. The ASAM MCD-3 MC API is specified in an object-oriented but technology-independent UML model and mapped to DCOM. This configuration allows easily addition of new programming language mappings to the standard without having to change the core of the standard.
AVL LIST GmbH, BMW AG, Continental Automotive GmbH, D2T, Daimler AG, dSPACE GmbH, ETAS GmbH, HORIBA GmbH, imc meßsysteme GmbH, M&K Mess- und Kommunikationstechnik GmbH, Porsche AG, Robert Bosch GmbH, Vector Informatik GmbH, Visu-IT! GmbH.