Modular Conveyor System

Self-driven, electric e-Carts from Krups Fördersysteme optimize the assembly and testing track in the battery pack production of a German car manufacturer; Turck's robust IP67 PLCs provide the decentralized operation control

Decentralized control for modular conveyor systems

Krups uses a concept with a few standard modules: Rotate modules, shuttle modules, stopper modules and indexers. Today each module operates externally as a black box, which simply communicates bidirectionally with the central controller in both directions via a bus connection. In-house, Krups calls these conveyor system modules which have their own intelligence smart modules. The company therefore looked for autonomous controllers ten years ago, which can be installed directly on the modules.

Since Turck launched its TBEN-L-PLC block controller on the market a few years ago, Krups has been able to save the effort required for a self-build. The company is now using the IP67 controller in many machine models – not only in the e-Cart system. The communication to the drives or valve blocks and other components of the module is implemented via a bus interface, while the communication to the main controller is mostly implemented via Profinet.

“We now have the benefit: The modules can be deployed immediately and without the need for any other field programming device, i.e. replace, insert, data backup,” explains Christian Mies, control developer at Krups. In addition, the range of protocols offered by the compact controller pays for itself.

e-Cart system saves power in battery production

For the battery pack production of a German car manufacturer, Krups realized a conveyor system with 130 self-driven carts, a kilometer of conveyor track, 70 turntables and around 140 stoppers. 10 stoppers use a TBEN-L-PLC jointly as a gateway to the customer's main controller. This considerably reduces the number of bus nodes required for the customer.

Unlike most conventional systems it is possible to communicate with the carts of the e-Cart system. NFC (near field communication) units are provided at the stoppers in order to use the TBEN-L-PLC as a gateway to implement communication between the main controller and the carts. In this way, carts can be removed depending on their state or the presence of warning messages. Another benefit: When the carts are waiting, they do not consume any power.

Less wiring due to IP67

Krups has recognized the work that can be saved with the IP67 technology. “Just routing the 24V cables and signals to the twelve controllers on the stoppers and labeling would be very labor intensive. The price of the TBEN-L-PLC covers this easily,” IT manager Christian Mies expresses his appreciation. The e-Cart system is not only energy-saving and fail-safe, it also enables more flexible processes as outlined in Industry 4.0 model scenarios and also already implemented.