A manufacturer of automated conveyor systems uses RFID technology to monitor the location of items and to route them to their chosen destinations. As a basket, fitted with an RFID transponder tag, travels through the warehouse, IO-Link-enabled high-frequency read-write modules (RWMs) monitor its position and read pre-set data stored in the tag. Local logic capability enables a read-write module to trigger a conveyor diverter, routing the item without reference to a centralised PLC-based control system.
An OEM manufacturer of automated conveyor systems for the distribution sector uses RFID technology to monitor the location of items as they pass through a warehouse. Designers also required local control of two-way conveyor diverters to route items to the correct destination;. Therefore generic information stored on each RFID transponder tag determines the required diverter position and thus an item’s destination.Location monitoring relies on a plant-wide PLC-based control system. An industry-standard interface with the RFID modules is highly desirable as this allows the use of existing libraries of PLC function blocks, avoiding the need for custom PLC code. Ultra-high-speed communication is not essential as conveyor speeds are moderate.Local diverter switching relies solely on the information contained in an item’s RFID tag; communication with the centralised system is unnecessary. Response time must be no more than 200 milliseconds to allow the diverter to operate before the item reaches the switch point.
IO-Link-enabled high-frequency (HF) read-write modules (RWMs) and RFID tags from Contrinex are ideal for this application. IO-Link-enabled RWMs are capable of meeting both requirements, allowing commonality of RWM hardware across the entire installation. With data-transfer rates up to 38.4 kbaud (COM2) in IO-Link mode, communication speeds are well in excess of the minimum requirement.
Contrinex IO-Link RWMs are configurable to operate in one of two discrete modes; IO-Link mode allows remote communication via the standard protocol, while standard I/O mode (SIO mode) allows the device to function as a smart condition-detection sensor. Process engineers can switch RWMs between modes either remotely, using the IO-Link protocol itself, or locally, using a pre-configured RFID tag (a Master Tag) which is applied directly in front of the RWM at start-up.While in SIO mode, RWMs operate either as simple presence-detection sensors, with a single switched output, or as two-state condition-detection sensors with two PNP outputs that correspond to pre-set generic values saved to an item’s RFID. In the event of a match, an RWM instructs a diverter to assume one of two alternative switched positions.With sensing distances up to 60mm, robust M18- and M30-threaded metal housings and integral M12 connectors, Contrinex RWMs are ideally suited to the environment of a busy industrial warehouse. They are compatible with all ISO/IEC 15693 approved RFID tags, allowing designers flexibility and value for money.