Data storage in assembly technology Content
Identification and data storage systems are used for controlling numerous production and transport systems in assembly technology. On the one hand, data related to objects is the basis for targeted control of process and processing steps and, on the other, is used for type or variant-dependent infeeding and outfeeding of workpiece pallets when manufacturing product variants on flexible assembly systems with branches. Two basic principles are used for dealing with data related to workpieces:
Central data storage: Based on a central collection of all workpiece-relevant data. Reliable identification of the workpiece at the processing station is required so that the appropriate data can be called up from the central data storage. Decentral data storage: Based on mobile data tag systems, where the workpiece-relevant data is sent along directly with the workpiece (or on the workpiece pallet). Powerful read and write heads that can read out or modify the information are needed at the processing stations.
With central data storage, the data related to the process and product is centrally collected. Mobile data tags on the workpiece pallet, as well as the appropriate reading devices, ensure reliable identification of the workpieces at the processing stations. Using the workpiece ID, the appropriate data set is indexed to load the data in the PLC or cell control. The cell control unit reads out the product type (variants, order or production lot) and the corresponding manufacturing status. This information is used to indicate whether any process steps are necessary and which ones. At the end, after finishing in the processing station, the information in the data set is supplemented. The data flow between the processing station and the host process requires a network.
With decentral data storage, the data related to the process and product accompanies the workpiece. To do this, the workpiece pallet are equipped with a mobile data tag with a large storage capacity that offers the option to read and write data. The data is always up-to-date at every processing station thanks to the read/write heads that can read out and edit data at any time. The individual stations can thus carry out the production processes independently; a network is not necessary for the workpiece data.
The enables users to implement RFID solutions with central or decentral data storage. This Plug-and-Run solution is available to all Rexroth transfer systems and the VarioFlow chain conveyor system. The new Rexroth identification system ID 200 offers a wide variety of interfaces that include EtherNet/IP, PROFINET, as well as PROFIBUS. The use of standardised frequencies and transfer protocols makes it possible to use common data tags. Thus, the ID 200 will be an inexpensive, economical solution for future tasks, as well.