Drive data acquisition for controller internal monitoring functions

Abstract

With the current trend of increasing automation, leading to self-organizing machine tools and production machines (“Industry 4.0”), data acquisition and processing becomes more and more important. Based on these data, new monitoring functions and identification methods can be implemented in the machine control. Depending on the algorithms, also drive internal data, such as the actual torque, or the power consumption of the machine axes are required, partially at high sample rates. State of the art computerized numerical controllers (e.g. SIEMENS 840D sl) however, are characterized by a separation of drive system and controller. Drive data, which is not included in the standard bus-connection are difficult to access by the superordinated CNC. The paper addresses this problem, presents and compares various concepts of drive data transfer to a standard industrial CNC/PLC. Subsequently, the most convenient method, which utilizes a drive-internal data recorder is chosen for implementation. It offers flexible drive data acquisition through the PLC at high sample rates, carried out block wise. Experimental results are shown to prove the functionality. Finally, ideas for continuative monitoring and identification methods are discussed