Encoders and interfaces_EN-Version 2

Contrary to initial persuasion, up to now there is no standard fieldbus but almost 50 different systems with deterministic characteristics regarding technical functions, application and popularity. But not every bus fits industrial use (fig. 1). Fig. 1: Encoder installed at a straightening machine in a sheet metal processing application. Multiturn absolute encoders with modular bus covers for convenient mounting and cost-effective maintenance have proven reliable even in harsh environments. Fig. 1a: Even when already docked the bus cover enables function-relevant parameterization or parameter verification. In sheet metal processing the easy-tomount encoders – here with Profibus interface – are applied as position sensors in an automated manufacturing process, for example tool positioning or precise straightening of sheet metal. Reliable, established systems well suited for rugged encoder applications are Profibus, Interbus, CAN, CANopen, DeviceNet and also latest interface technology enabling a network on Ethernet level (fig. 2). Fig. 2a: Nearly no industry that does not rely on fieldbus communication-whether food and beverage, packaging or material handling. Fig. 2b: Construction sites often provide only confined space, reason why at truck-mounted concrete pumps often only two support legs are extended. The operating range at the supported side of the vehicle is safely monitored by CANopen encoders. (Photograph: Schwing GmbH) The bus interface truly applied in the end does mainly depend on the already prevailing control topology. Efficiency and safety are primary conditions for the generation of renewable energy. High-performance fieldbus interfaces (fig.