Overhead conveyors are used to transport workpieces in many production plants. One frequent area of use is the automotive industry. The advantages of overhead conveyors include the fact that the floor remains accessible and that they can be mounted at an ergonomically optimal height. The speed of the overhead conveyors is usually less than one meter per second. Their drive motors produce strong electromagnetic interference fields.
For targeted control of the manufacturing processes, workpieces on the conveyor system need to be automatically identified and assigned. Based on this information, the required auxiliary processes and manufacturing steps are then initiated by the process control. In addition, defective or incorrectly assigned products can be automatically ejected. To ensure these processes happen, the individual hanger attachments must be detected and identified as they pass specific points.
RFID read/write heads are mounted in decentralized fashion at the defined points and connected to the fieldbus or the plant control system. With the correct sensor design, the sensors’ function will not be affected by the surrounding electromagnetic fields. With an appropriate reading range selected, the RFID read/write head reliably reads the data from the tag as the hanger attachments pass. Tags with a ferrite core allow direct mounting on metal and flush-mounted, protected installation on the hanger attachment. With typical speeds for overhead conveyors, it is usually not necessary to adjust the reading time but this is possible if needed. The FP series RFID read/write heads are ideally suited for installation in monorail conveyors.
IQH1-FP-V1 read/write head
Perfect shielding is achieved in combination with the IDENTControl control interface and with shielded connection cables. Identification via RFID enables localization of the workpieces at any time and can be used for optimized control. The writable tags are rugged and provide the basis for a long-lasting solution. Defective products can be ejected automatically.