One of SAFELOG GmbH’s core competencies is the development of efficient and failsafe solutions for picking systems. A particular focus is on pick-by-light and put-to-light technology. This technology is perfect for picking small and medium-sized parts. The system uses optical signals for the operator to indicate the correct pick and put position. The system immediately detects and communicates an operating error. To continue the picking process, the operator must correct the error. Consequently, the workflow can continuously be improved according to the poka-yoke principle for error prevention. For visualization, SAFELOG uses ASi-5 compartment displays and ASi-5 eTag display modules as signal lamps and confirmation buttons.

Picking system based on building blocks

SAFELOG’s individual picking system components can be flexibly combined. This enables customized solutions. Moreover, using these components, even existing systems can be modified or expanded at any time. The key is the ASi-5 communication technology, connecting the control unit with an integrated touchscreen to up to 96 receiver devices via a unique two-conductor profile cable.

As part of the control unit, the AS-Interface master manages the data traffic on the AS-Interface network. An ASi-5 module is used as an interface on the individual compartment displays or display modules. This way, each device can easily be connected to the system. A wide variety of topologies can be implemented, such as tree, ring, star, or line/bus structures. Each connected device receives its individual frequency channel to communicate with the master.

ASi-5 – a cable makes the difference

ASi-5 is a so-called fieldbus – a bus system connecting sensors and actuators to the ASInterface master to exchange information – with or without an integrated fieldbus interface. Here, the distinct feature is a unique two-conductor profile cable. The cable transmits information to connected devices and simultaneously provides power to the individual components. In particular, the cable reduces wiring efforts and provides a free choice of topology. Compared to version ASi-3, the new generation ASi-5 can transmit significantly larger data widths in a considerably shorter time and with a substantially larger number of connected devices. Furthermore, ASi-5 communicates on a different frequency range than ASi-3. Therefore, the new standard can be integrated into an existing AS-Interface bus topology without complications.

Mercedes-Benz benefits from new standards at SAFELOG

ASi-5 technology is now standard in every SAFELOG product. The technology was first used in a Mercedes-Benz Group AG greenfield project – Factory 56. In addition to an AGV system, the company from Markt Schwaben provided a pick-by-light system. The ASi- 5 components were installed and commissioned in cooperation with the experts from Bihl+Wiedemann GmbH. “This major project for Mercedes-Benz started shortly after the introduction of ASi-5. Here, the technology was first and concurrently very successfully used,” Frank Lelonek, branch manager at SAFELOG, explains. “This project’s distinct challenge for us was to provide the first high-quality devices for industrial usage right after the introduction of ASi-5 technology at the SPS 2019
trade show,” Sven Meister, key account manager of automotive at Bihl+Wiedemann, adds. “This was partly possible because, as an ASi- 5 development group participant, we naturally knew which applications were now possible with the new ASi-5 ASIC.”

Increased data width and a more flexible storage system

Due to ASi-5’s significantly increased data width compared to ASi-3, where it is limited to 4 bits per module, employing the pick-by-light system enabled the implementation of two applications. For one, a display with four RGB lighting segments and a pushbutton for the individual compartments was implemented. To individually control display lights, 12 bits of data are required.
In addition, so-called eTag display modules are used. Equipped with two pushbuttons and two RGB lighting elements, the modules replace the standard paper labels on storage locations with displays that can be reprogrammed as needed, making the entire storage system significantly more flexible. The control and the transmission of the display signals are also done through ASi-5.

Please refer here for additional information on using AS-Interface communication technology in SAFELOG’s picking systems.