RFID Technology Solutions

What is RFID?

RFID (Radio Frequency Identification) identifies objects by radio. A transponder, also called a tag or label, carries a unique ID and optionally further data. A reader powers passive tags through its radio field and reads them without line of sight and without a battery in the tag. Range and use cases differ considerably by frequency band: LF (125 to 134 kHz) for a few centimetres, HF (13.56 MHz, related to NFC) up to about one metre, and UHF (865 to 868 MHz in Europe) for several metres and reading many tags at once.

How RFID is used in the IIoT

In industry, RFID links physical objects to their digital data. Typical applications include identifying load carriers and containers in material flow, tracing components through production, identifying tools at the machine, stocktaking in the warehouse and automatic booking at goods receipt. RFID readers with IO-Link, Profinet or OPC UA interfaces pass the IDs they read directly to the controller or MES, so each read automatically triggers or documents a process step.

RFID, barcode or real-time location?

A barcode or QR code is cheaper but needs line of sight and is scanned one at a time. RFID reads without line of sight, even through packaging, and in the UHF band captures many objects at once. RFID only tells you that an object passed a read point, though. If you need to know where something is in the hall right now, you need real-time location with UWB or Bluetooth. The omlox standard connects both worlds.

How an RFID system is structured

An RFID system consists of tags on the objects, antennas at the read points, a reader and software that assigns the IDs read to a process. Read points sit where objects move: at gates, conveyors, shelves, machine stations or as a handheld reader with the operator. Middleware filters duplicate reads and passes only relevant events to the ERP, MES or WMS. Depending on type, tags can be written once or multiple times, for example with test data or production parameters.

What to consider when choosing

The frequency band follows from the application: short-range tool identification points to HF or LF, bulk reading of pallets and containers to UHF. Metal and liquids interfere with the radio field, which is why special on-metal tags exist. Read rates depend heavily on antenna position, tag orientation and environment and should be tested on site before rollout. Finally, integration matters: a read point only adds value once its data reaches the ERP, MES or WMS.