Protecting the operator and getting high productivity are not opposing concepts on this Cambopak multipack machine at contract packager Van Genechten Nicolaus GmbH in Kempten, Germany—thanks to integrated safety and process control. The IndraDrives from Bosch Rexroth driving the four servo axes execute all of the important safety functions on a decentralized basis. Consequently, responses to faults are fast, thereby protecting operators from the highly dynamic servo drives, as they organize the bottles of a milk-based beverage into rows, wrap them with carton board, and glue the package together. A “safely reduced velocity” function on the drives can allow the machine to continue working in certain circumstances until the operator resolves a problem. Moreover, no hardware or detours through the control system means no power contactors in motor supply lines and less cabling in the control cabinet.
Meanwhile, a programmable logic controller (PLC) coordinates the functional groups, including those for the electronic cams. Data relevant to the user passes through a control station, and a Sercos interface (for Serial Real-time Communication System) guarantees simple scalability. Servers using the OPC open connectivity standard are available to connect the machine to human-machine interfaces and the central computer, and Profibus-DP allows communication with a higher-level PLC. Packaging experts at Bosch Rexroth worked with engineers at Wilhelm Fischer Special Machines GmbH of Durach, Germany, in developing the system.