Industrial users therefore demand extended diagnostic capabilities.
Tough calls at cell networking
Practical experience suggests orienting the selection of network components to specific applications, rather than to the complex parameter configuration of universal network components. This calls for defining the typical applications in unit networking. Network components contain a pre-selection of parameters that are optically attuned to application requirements. These parameters cannot only be requested from network diagnostics or web-based management, but may also be read locally at the device. In this way, users are assured of the integration of basic functionalities in the operation of a given machine.
International standardisation
If networks are expediently structured from the viewpoint of industrial buildings, and also that of automation units, the current standardisation topics can easily be assigned accordingly. IEC 11801 represents the international standard for application-independent, structured IT wiring. The high level of acceptance of this standard is based, for one, on the three networking levels (primary, secondary, tertiary), and secondly on its application-independent approach, which has enabled communication of diverse services on the network. In practical applications, this has evolved into a quasi standard in communications. Ethernet is now deployed in over 90 per cent of the local area network (LAN) topologies. Transferring this standard to the conditions of an industrial environment, yields a standard for industrial buildings. This process was already initiated in 1999 by German standardisation institutes. A draft dealing with industrial wiring will be available shortly under ISO/IEC 24702. ISO/IEC 24702 sets the focus on networks in industrial buildings, rather than on unit networking. This subnet is part of the building, and supports vertical integration within this building. The production units contain autarkic areas, which are individually adapted to the production process. These areas cannot be forced into the rigid structure of a building network. Consequently, the various field bus organisations have developed their own directives, which usually preserve the installation within automation units. This outlet, referred to as apparatus outlet (AO) in the industrial arena, segments the networks.
The existence of these autarkic networks is confirmed within international standardisation by the current trends in standardisation. Both networks, however, must be interconnected via defined interfaces. Users benefit from the targeted deployment of Ethernet in the industrial arena, which enables significant innovation gains, based on synergies with office technologies. Network convergence is given by the performance and integration of field bus profiles. In this way, Ethernet forms a high-performance field bus system.
In order to make such added value available to industrial users, the focus must be set on defined applications. As a result, only specially developed components can be integrated into applications for a product cell network. Expert IT know-how should not, however, represent the prerequisite for the utilisation of such components.
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