ASAM GDI

ASAM GDI (Generic Device Interface) was developed for providing an independent integration interface between measurement & control devices and test bed automation systems. Previously, this area was characterized by an almost unmanageable number of individual and incompatible devices. Integration of devices depended strongly on the availability of device drivers for specific operating systems, physical interfaces and protocols. Since test beds have a long lifetime, devices of different generations had to coexist in one system. All this caused high integration efforts, whenever a device had to be integrated or exchanged in an existing test bed system.

The goal of the standardization was to reduce cost and time efforts for the creation, support and maintenance of such complex automation systems and their measurement and control devices. Ideally, a new device would be integrated in a plug-and-play fashion with minimal to no integration efforts. Therefore, the GDI standard defines a four-layer architecture:

• Layer 4 - Coordinator Services: Coordinator services provide a device-neutral interface for application programs. They connect application programs to device drivers. The coordinator is configured via a parameterization instance description file (PID), which contains an abstract description of data sinks and sources of the application layer and how they are connected to the device drivers of layer 3.
• Layer 3 - Device Drivers: Device drivers provide a generalized and platform-neutral interface between the coordinator (layer 4) and the devices' specific functions (layer 2). A device driver provides uniform, virtualized access to the device's functions via a model of the devices functionality and internal states. A device driver is described by a device capability description file (DCD).
• Layer 2 - Platform Adapter: The platform adapter provides an OS-specific interface between the generalized device driver (layer 3) and the peripheral or communication driver (layer 1).
• Layer 1 - Platform Adapter Extension: The platform adapter extension includes physical connections to the peripheral hardware and communication type specific interfaces. GDI includes the transport layer and communication types for communicating with devices via IPv4, USB, SoftSync, COM or LPT.

This approach abstracts the test bed automation system from the operating system, communication busses, protocols and measurement & control devices. As a result, ASAM GDI allows a device-independent application execution and application-independent device integration. This allows quickly exchanging devices in existing test beds, or conversely migrating to a new test automation system with less effort while still using existing measurement & control devices.

ASAM GDI is used in chassis dynamometers, engine dynamometers, emission test benches and transmission test beds. Furthermore, GDI-compliant devices are used in car assembly lines, e.g. for fluid-filling stations, and in service areas where miscellaneous measurement modules are integrated into a shop floor tester. The standard is also used for the integration of data loggers and measurement modules for supplier-independent device configuration.

The most recent version, ASAM GDI 4.5.0 was released in 2011. This version includes the parameterization instance description (PID) file format in XML, which provides a mapping of required application functionalities onto device functionalities. The PID file allows exchanging a device in a testing system without needing to make any modifications to the test bed automation software. Furthermore, the latest ASAM GDI version was harmonized with the corresponding ISO Standard 20242.

Standard Authors

AVL LIST GmbH, BMW AG, Daimler AG, dSPACE GmbH, FEV Automatisierungssysteme GmbH, General Motors Company, imc Meßsysteme GmbH, Elektrobit Automotive GmbH, HORIBA Automotive Test Systems GmbH, MFP GmbH, M&K GmbH, National Instruments Corporation, Porsche AG, rd electronic GmbH, Renault S.A., Siemens AG, Volkswagen AG.