RFID systems provide precise object data in real time, thereby creating transparency that enables confident decision-making and efficient processes in production and logistics.
RFID (Radio Frequency Identification) is a contactless identification technology based on electromagnetic fields. RFID transponders (tags) are typically passive and are powered wirelessly by the reader’s field. The captured data is transmitted via radio waves, without any visual contact. This enables robust, low-maintenance, and real-time object tracking.
An RFID system consists of a transponder (also known as a data carrier or tag) and a reader equipped with an antenna. Depending on the frequency range used, energy and data are transmitted either via inductive coupling in the LF and HF ranges or via electromagnetic waves in the UHF range. The transponder is activated exclusively within the reader’s electromagnetic field and transmits its stored information contactlessly to the reader. This technology enables contactless identification without a line of sight, typically operates without a battery in the transponder, and allows for the simultaneous reading of multiple transponders in the UHF band. RFID systems are also characterized by their high resistance to dirt, dust, and light, support both read and write operations, and are particularly suitable for real-time and automation applications. Thus, RFID provides the technical foundation for reliable, automated, and data-driven identification of objects—especially in applications where traditional identification technologies reach their limits.
HF and UHF RFID differ fundamentally in their frequency ranges and the associated physical methods of energy and data transmission.
HF RFID (High Frequency, 13.56 MHz) operates using inductive coupling in the near field. The reader generates an alternating magnetic field from which the transponder draws its energy. Communication is stable and defined over short distances, typically in the range of centimeters to decimeters. HF systems are considered particularly robust against environmental influences such as metal or liquids and offer high process reliability at clearly defined read points. Due to its limited range and lower data throughput, HF RFID is particularly suitable for applications within production facilities and machines, at individual transfer points, or wherever targeted individual identification is required.
UHF RFID (Ultra High Frequency, approx. 860–960 MHz), on the other hand, uses electromagnetic radio waves in the far field. The transponder is powered by the radio signal emitted by the reader. This enables significantly greater ranges of several meters, as well as the simultaneous detection of many transponders at once, a process known as batch reading. UHF RFID enables high read speeds and is ideally suited for high-throughput applications, such as in logistics, warehousing, or the end-to-end tracking of objects across multiple process steps. At the same time, however, UHF is more sensitive to environmental conditions: materials such as metal or liquids can attenuate, reflect, or distort the radio field, which is why the selection of suitable tags and careful system design are crucial.
In summary, the advantage of HF RFID lies in its stability and controllability at short distances, while UHF RFID excels in range, speed, and multi-tag capability. The choice of frequency band is therefore less a question of technology and more a matter of application: HF is suitable for precise, locally confined identification tasks, while UHF is ideal for transparent, data-intensive processes over longer distances.
RFID systems differ in production and logistics primarily in terms of their role in the process.
In production systems, RFID is typically designed to be process-oriented, deterministic, and locally confined. The goal is the reliable identification and assignment of products, components, or workpiece carriers within clearly defined production steps. Data capture takes place at fixed reading points in machines or systems, often using HF technology, as short ranges, high robustness, and repeatability are required. The data collected is processed directly in the control system and serves as the basis for functions such as variant control, recipe selection, or the validation of individual process steps. Here, RFID supports flexible, error-free production and helps reduce manual intervention, scrap, and production errors.
In logistics systems, the focus is on transparency and end-to-end traceability. RFID is used to automatically track transport units such as pallets, containers, or shipments and to make the movement of goods visible throughout the supply chain. UHF systems with larger read ranges are frequently used, such as gate, tunnel, or portal solutions, which also enable the simultaneous reading of multiple transponders. Here, RFID primarily serves data verification and inventory management and is closely linked to higher-level systems such as WMS, ERP, or track-and-trace solutions. The goal is to prevent shipping and picking errors, accurately map inventory, and reduce manual scanning processes.
TURCK RFID systems capture identification and application data via HF read/write heads or UHF readers and make this data available to higher-level systems via RFID interfaces. The data is processed within the interface, which acts as a bridge between the field level and the control or IT level.
Connection to controllers
Integration into a PLC typically occurs via Ethernet-based fieldbuses such as Profinet, EtherNet/IP, or Modbus TCP. RFID data is available to the controller as process data or via defined command mechanisms and can be directly integrated into the control sequence.
OPC UA for MES and ERP
For communication with MES, SCADA, or ERP systems, corresponding TURCK RFID interfaces provide an integrated OPC UA server. The RFID data is mapped in a standardized information model and can be read by OPC UA clients or specifically queried via methods. This enables system- and manufacturer-independent integration at the IT level.
MQTT for IIoT applications
MQTT can be used for event-based and cloud-near applications. RFID events or status information are transmitted as messages to an MQTT broker and are available there to any subscribers for further processing, for example for monitoring, analysis, or tracking applications.
Barcode- and RFID-based identification solutions differ fundamentally in terms of process reliability, performance, and the degree of automation. Whether barcode or RFID is the better choice therefore always depends on the requirements of the specific application.
Barcode systems are considered a cost-effective entry point and can be easily integrated into existing IT and logistics processes. They require minimal infrastructure and are sufficient for many applications. However, visual contact between the code and the scanner is always necessary for reading. Dirty, damaged, or misaligned labels can make scanning difficult, and simultaneous reading of multiple objects is not possible. This limits the degree of automation.
RFID solutions come into play where higher process reliability and automation are required. Identification takes place contactlessly and without line-of-sight, and simultaneous detection of multiple transponders is possible. This allows workflows to be largely automated and reduces manual steps. RFID provides reliable inventory and process data in near real time, thereby increasing transparency and security in production and logistics. This comes at the cost of higher investment expenses; furthermore, deployment in certain environments—such as those with a lot of metal or liquids—is technically more challenging.
The selection of a suitable RFID tag depends primarily on the following six factors:
1. Environmental conditions
RFID tags must be compatible with their environment: Only M-variants are suitable for metal; others require spacers. Temperature ranges extend from –25…+85°C up to high-temperature tags that can withstand temperatures of up to 240°C for short periods. Protection ratings vary from IP40 (labels) to IP69K (industrial round tags).
2. Memory size & memory type
EEPROM tags (128–320 bytes) are suitable for small amounts of data and infrequent writing, whereas FRAM tags (2–8 kB) enable an extremely high number of cycles and fast read/write operations, making them ideal for frequent updates or fast processes.
3. Design & Mounting
Typical options include rugged screw-on tags, universal round tags, compact miniature tags, as well as labels or inlays for less demanding environments. The appropriate design depends on available installation space, mechanical stress, and desired replaceability.
4. Range & Combination
The range depends directly on tag size, design, and the read/write head used. Larger tags offer larger transmission zones; metal and unfavorable installation positions reduce the range.
5. Application Dynamics
In moving applications (“on the fly”), short read/write times and sufficient dwell time are critical. FRAM tags offer advantages here through faster access times and high cycle stability.
6. Compatibility & Standards
RFID tags must comply with ISO 15693 and be compatible with the read/write head used. ATEX-certified variants are required for potentially explosive atmospheres.
The selection of a suitable UHF tag depends primarily on the following six factors:
1. Environmental conditions
UHF is sensitive to its environment: Metal and liquids affect the field significantly more than they do with HF. Therefore, UHF tags must be specifically designed for metal environments (on-metal tags). Protection ratings range from IP40 (labels) to IP67/69K for industrial applications; high-temperature variants are also available. Country-specific frequency ranges (e.g., EU 865–868 MHz, USA 902–928 MHz) must be taken into account.
2. Memory Size & Memory Type
UHF tags typically offer smaller user memory areas (e.g., 28–110 bytes) than HF tags, but utilize structured memory banks according to EPC Gen2 (Reserved, EPC/UII, TID, User Memory). The memory is sufficient for EPC-based identification and moderate amounts of additional information; UHF tags are less suitable for large data volumes.
3. Design & Mounting
UHF tags are available as on-metal tags, industrial designs, self-adhesive labels, inlays, or rugged screw/bolt tags. The design has a massive impact on range: larger antenna surfaces mean more stable performance and greater distance. The mounting orientation (horizontal/vertical polarization) is critical for readability.
4. Range & Combination
UHF enables ranges of several meters, depending on the tag design, the reader antenna, transmit power, and environmental conditions. Write ranges are significantly shorter than read ranges. UHF fields are inhomogeneous—reflections, fading, and interference must be taken into account. The actual range is typically 40–80% of laboratory values.
5. Application Dynamics
UHF is ideal for fast and dynamic processes: batch reading of up to 200 tags per second is possible. When tags are in motion (“on the fly”), sufficient time windows must be allowed for retries. Minimum distances between tags (typically ≥ 50 mm) improve readability. Multiple readers can also interfere with each other, so frequency management and synchronization are important.
6. Compatibility & Standards
UHF tags must comply with ISO 18000-6C / EPC Class 1 Gen 2. Regional radio approvals such as CE, FCC, IC, KCC, etc., depend on frequency and transmit power. ATEX-compliant variants are available for potentially explosive atmospheres. Compatibility with TURCK readers (Q series, large surface antennas) and TBEN-BL-Ident interfaces must be ensured.
With TURCK's RF bus mode, up to 32 RF read/write heads can be efficiently networked per channel—ideal for large-scale RFID applications with minimal cabling.
TURCK's read/write heads achieve above-average ranges, particularly in the HF range, thereby outperforming many comparable solutions on the market.
Turck not only offers a wide range of RFID solutions for manufacturing and logistics, but also provides turnkey solutions including software integration through Turck Vilant Systems.
Turck Vilant Systems (TVS) is the specialist for turnkey identification and localization solutions within the TURCK Group — serving logistics and intralogistics applications worldwide and across all industries. From initial consulting and process analysis to go‑live and productive operation, the team supports every project end‑to‑end. With deep process expertise and proven in‑house software for data pre‑processing, TVS delivers tailored track‑and‑trace solutions with short implementation times, high operational reliability, and minimal development effort.
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