If you need to uniquely identify a production object for material flow control, a data carrier will be required. This could be an RFID or barcode label or imprinted barcode.
As the object with the data carrier moves through production, a reader located wherever the object needs to be identified can read out the data (such as a serial number) from the data carrier. This data is sent to a processor unit which in turn passes it on to a PLC, PC or higher IT level. The data can then be used to make decisions about production or quality.
There are basically two technologies available to you for identification: RFID, Radio Frequency Identification, which uses radio waves and barcode readers, which record images which you analyze in software.
RFID systems are either ultra-high frequency (UHF), high frequency (HF) or low frequency (LF). They typically consist of three components: Data carriers (for data storage), read/write head or antenna (for data transmission) and processor unit (for data communication).
- UHF provides communication with data carriers over up to 6 m of range with simultaneous reading of multiple data carriers (multi-tagging).
- HF with its high speed enables parts tracking at close range up to 400 mm. Data carriers have various properties (e.g. for high temperature, with large memory capacity and for attaching to metal).
- LF data carriers are ideal for challenging conditions, such as in metallic surroundings. They are therefore often used in tool identification.
Barcode readers read 1D and 2D barcodes. Their range is from a few millimeters up to several meters.
Asset tracking – Tracking goods using RFID and barcode readers
Work-in-Progress – Monitoring production in automated assembly using RFID
Intralogistics – Controlling the material flow across areas
E-Kanban – Ensuring material supply on the production line using RFID
Basics – Definitions
Product range – RFID
Product range – Machine vision and optical identification
Identification – An introduction