Guide to RAIN RFID (radio-frequency identification) readers and tags

What you need to know about use, function, advantages and choosing the right RFID systems for you. Also read expertise about RFID readers, transponders and antennas.

What is RFID and how does it work?

RFID stands for "Radio Frequency Identification" - the contactless identification of objects and living beings by means of radio or radio waves. Basically, there are three relevant RFID frequency ranges worldwide and the associated standards:

• LF RFID 125 KHz
• HF RFID 13,56 MHz
• UHF RFID 865 – 928 MHz

An RFID reading station essentially consists of three components:

• an RFID transponder on the object to be detected with an integrated antenna and RFID memory chip, on which the respective data can be written or read.
• an RFID antenna that generates the electromagnetic radio field for energy and data transmission.
• an RFID read/write device, the so-called RFID reader, with which digital data on the RFID chip of the transponder can either only be read or also written. Intelligent RFID readers can also filter the data and forward it to higher-level IT systems.

As soon as the RFID transponder is within the range of a reader, the RFID reader builds up an electromagnetic field with its internal or also external antenna(s), which supplies the RFID transponder with energy and activates it so that data can be transmitted wirelessly and bidirectionally.

RFID is one of the basic technologies for the digitalization of material and production flow processes, for the registration of vehicles in toll systems, control of access systems in parking garages or as an electronic nameplate on machines and systems. Thanks to an intelligent design, RFID enables fully automatic data generation, which leads to an increase in efficiency, a minimization of errors and cost savings.

The following application examples are applicable regardless of industry and sector. The example scenarios mentioned clearly show which RFID potentials can be tapped.

Intralogistik and Supply Chain Management

In both internal and external material flows, RFID technology creates transparency with regard to goods, assets and raw materials as well as their path in supply chains - from the warehouse to production, from the shipper to the customer. In addition, goods identification via RFID ensures seamless traceability. RFID systems are also used as driver assistance systems on forklift trucks.

RFID Load Carrier Management

The following load carrier information is mandatory for efficient and transparent digitized load carrier management:

• Total number of load carriers
• Position of the load carriers
• Status of load carriers: full, empty, defective, in service, etc.
• Availability of the load carriers

Which load carriers can be tracked seamlessly and transparently using RFID? In principle, any load carrier if a suitable RFID transponder has been selected depending on the external environmental conditions that can withstand thermal, chemical or mechanical stresses.

Load carriers marked with RFID, such as Euro pallets, small load carriers KLT, electroplating or powder coating racks, can be detected zone by zone by means of corresponding RFID reading points in logistics or production. The data to be generated then determines the zone-specific position of the RFID reading points - e.g. entry and exit of empties, transition from production to warehouse, provision before or after a production line or of specific process steps.

The detection points of the load carriers not only generate location information, but also provide information on the status of the load carrier, such as filled, emptied, available or blocked. Historical data is also generated, such as the number of runs of a load carrier, so that it can be revised in good time.

Inventory management and localization

RFID technology is suitable for automatically detecting goods - even without direct visual contact. Assets can be recorded and managed individually or in batches on a pallet or in another container. This improves inventory accuracy and reduces inventory effort. As object identifiers, RFID transponders in real-time localization systems such as RTLS (Real-Time Location System) from Kathrein Solutions contribute to transparency in production-related and intralogistics material flow and asset management.

Read more about the Kathrein Solutions RTLS system here or read our RTLS guide.

RFID-eKanBan

The following potentials are offered by eKanBan when using RFID-tagged containers:

• Availability of C-parts on production lines or production islands
• Automatic replenishment
• Inventory security by means of automatic material flow bookings
• Working time savings through automatic material flow or container bookings

The digitized containers marked with RFID transport physical units and data. These are stored in the RFID transponder and/or can be married with the RFID container ID in the leading system with information such as article number, batch number, production data or destination coordinates.
The data is generated by RFID capture points to automatically book and plausibilize putaways in C-part shelves.
Replenishment is automatically triggered by RFID capture or detection of the removal of empty totes from the C-division shelf. The RFID ID of the container provides information about the article number to be replenished.
Advantages of the RFID eKanBan:

• Saving of employee time for replenishment bookings
• Minimization of errors through automatic, correct RFID part number recording
• Timely triggering of the replenishment process: "Shelf reorders itself".
• Inventory minimization due to precise quantity recording
• Real-time recording of consumption on the production line
• Reduction of tied-up capital due to lower buffer stocks

Read the eKanBan Success Story here.

Production control, handling and assembly technology

RFID systems are used in manufacturing to automate the tracking of raw materials, parts and assemblies, and the control of production processes. In assembly plants, RFID enables automated handling and target control of containers. In machine tools, tools are identified by RFID chip and automatically inserted to match the machining job.

RFID production status and material flow postings in production

RFID-tagged finished parts, semi-finished parts or raw materials automatically register at production stages or production machines. RFID detection points automatically scan delivered material, finished or semi-finished parts, or even containers with corresponding bulk material or small parts.
The data captured by the RFID system is subjected to a thorough plausibility check. This check ensures, for example, that the correct material is available for the upcoming production order. It also ensures that the correct production stage has been reached and that no steps in the production process have been omitted. It also verifies that the delivered part or material has successfully passed quality inspection and received the appropriate release.
The material flow and order status posting takes place automatically after a positive plausibility check. The process described is repeated per manufacturing stage.

Access control and ticketing

RFID technology can be used to control access to buildings, as an exit control for managed or reserved parking areas, and as an electronic payment ticket for a wide variety of applications.

RFID as one of the world's leading technologies for vehicle detection in tolling and parking systems

RFID UHF systems according to the ISO 18000-6b and 6c standard form the technical framework for almost 60% of all toll systems worldwide. Passive RFID transponders, which are attached to the inside of the vehicle windshield or to the outside of a motorcycle headlight in the form of head lamp tags, allow vehicles traveling at speeds of up to 200 km/h to be detected quickly and securely using reading stations integrated into the road infrastructure.

Integrated payment systems allow secure transaction of toll fees, special RFID chips with AES 128 bit encryption prevent manipulation of the system.

RFID readers with integrated 4G/5G interfaces can also be cost-effectively integrated into existing energy infrastructure and enable fast implementation times.

Depending on the integrated UHF RFID chip, different amounts of data can be stored on different memory areas of the RFID transponders. The storage capacities of RFID transponders depend on the transponder chip type used.

When selecting the transponder, it is essential to consider the memory requirements needed by the planned application. This is usually done as part of an RFID feasibility study (RFID proof-of-concept).

More information about the RFID proof of concept

TID Memory (TID memory area):
All RAIN RFID UHF transponders also have a so-called TID memory area (Tag unique ID), which can only be read and contains special manufacturer information about the type of transponder. The TID memory is usually only 32bit in size.

Basic distinguishing features of RFID transponders are the type of communication standard (LF, HF, UHF) as well as the design of the transponder's construction - i.e. the packaging of the RFID antenna and the RFID transponder chip in the transponder housing.

There are two basic types of RFID transponders - active and passive. Active RFID transponders have their own power source, such as a built-in battery. Passive RFID transponders, on the other hand, draw their energy for data transmission exclusively from the electromagnetic field of the RFID reader or writer.

Active RFID Transponder

Active transponders do not require the induction of energy by radio waves, because they have their own energy supply - usually in the form of an integrated battery. This makes it possible to transmit data over long RFID ranges of up to 100 meters - a decisive criterion in some applications.

PACKAGING TYPES OF RFID TRANSPONDERS

Based on a basically identical inner life of RFID transponders with chip, antenna and, if applicable, battery, these electronic data carriers differ in the way they are packaged - and thus in their mechanical, thermal and chemical resistance.

RFID Hardtags (rugged housing)

In many applications, especially industrial and logistic applications, RFID chip and antenna are integrated and/or encapsulated in robust plastic or metal housings of various types and sizes in order to ensure the longest possible service life of the RFID tag through maximum mechanical, thermal and chemical load capacity. This design is also generally referred to as an RFID hard tag.

RFID- Windshield Transponder

Especially for use in toll collection, there are so-called windshield transponders that are optimized for mounting on the inside of a vehicle windshield. With a suitable reading infrastructure, reading ranges of up to 20 meters can be achieved.

For this type of transponder labels, many additional security functions (Tamper Evident / Tamper Proofed) are possible. These range from so-called pre-cuts at the ends of the label to hologram hologram inserts or fragile antenna structures that cause defined destruction when the label is removed.

The main component of an RFID reading point is the RFID read/write device, which is usually referred to as an RFID reader.

The RFID reader generates an electromagnetic field by means of an RFID antenna. The electromagnetic waves are received by the RFID transponder's antenna. The electrical energy induced in the process is transmitted to the RFID chip of the transponder. The transponder is thus able to send its data to the RFID reader's antenna via the RFID transponder antenna. Protocols embedded in the operating system of the RFID reader control the exchange of data on the so-called RFID air interface in order to read or write to the RFID transponder.

Both mobile RFID readers and stationary RFID readers are available to users. Depending on the type of application, either mobile or stationary RFID reading systems (RFID readers) are recommended in accordance with the processes to be mapped.

High RFID reading performance thanks to multiport RFID readers

Each RFID reader variant offers specific properties. Multiport RFID readers are used when RFID reading conditions are difficult or when a large number of RFID transponders must be read. In this case, the use of several RFID antennas per RFID reader enables electromagnetic waves to reach the RFID transponders to be read from different angles at different times in order to supply the transponder with energy and start the reading process. Intelligent RFID antennas also have the option of using different antenna polarizations and thus also increase the reading rate in difficult environments. The polarization is switched by means of a control signal on the antenna line. Multiple antenna combinations are primarily used in the field of logistics, e.g. to automate the booking of loading and loading processes using RFID.

RFID-Frequencies

RFID systems differ in their transmission frequencies. They are divided into the following frequency ranges:

• LF (Low Frequency, 125 kHz)
• HF (High Frequency, 13.56 MHz)
• UHF (Ultra High Frequency, 865 MHz to 928 MHz)

RFID in the LF band

In RFID systems in the LF band, data is exchanged in the 125 kHz frequency range. The worldwide standards are ISO/IEC 11784/85. Characteristic of LF RFID are the very small reading range of a few centimeters, the very good penetration of fabric and moisture and the high memory sizes in the transponders of up to 2048 bits. In the LF range, the so-called pulse reading of several transponders with one reading point is not possible. The LF RFID technology is very common in the application field of animal identification, waste management and in the automotive field for the keyless entry application.

RFID in the HF band

RFID systems can also be found in the HF frequency range at 13.56 MHz. The worldwide standards for this are ISO/IEC 14443 and ISO/IEC 15693. HF RFID systems are widely used in many different applications. The largest share is accounted for by the so-called NFC NearField Communication System in mobile devices. Other fields include automation technology for the detection of workpiece carriers and tools. The reading range of HF systems can be up to 70 cm, and pulse reading is now possible with the latest generation of HF systems.

RFID in the UHF band

The latest RFID technology operates in the UHF frequency range between 865 - 928 MHz, depending on world regions. The global communication standard is defined in ISO 18000-6C / EPC Gen2 V2 and allows worldwide interoperability. RFID UHF has some outstanding technical capabilities: passive UHF RFID transponders can be detected over long ranges of up to 20 meters, up to 500 transponders can be read per second in pulse applications, and they can be reliably detected on highways at speeds of up to 200 km/h. UHF technology is widely used in the logistics and retail sectors, as well as increasingly in vehicle detection and toll systems. In the healthcare sector, RFID UHF is used to monitor sterile garments or to locate special mobile devices and equipment indoors. Especially for security-relevant applications, transponders and readers with high encryption algorithms are available on the air interface.

RFID: uniformity through norms and standards

RFID technology is subject to a number of standards that ensure global and cross-vendor compatibility and interoperability of RFID systems.

• IEC 18000
  This series of standards describes various RFID technologies and protocols for wireless communication between transponders and readers.
• ISO/IEC 15693
  This standard describes an HF RFID system for the identification of objects at short distances.
• ISO/IEC 14443
  This standard deals with contactless RFID transponders and RFID readers used for short-range wireless data exchange.
• GS1
  GS1 is a network of not-for-profit organizations that develop, negotiate and maintain standards for inter-company processes worldwide.
• EPCglobal
  EPCglobal is an industrial consortium focused on developing standards for the use of Electronic Product Code (EPC). The EPC (Electronic Product Code) is a globally unique identification key that can be used to uniquely identify objects. It always consists of the GS1 base number, an object type and a serial number.

Standards for special applications
For a number of applications of RFID technology, special standards must also be observed, such as the global IATA standard RP1740C for the identification of airline baggage, VDA 5500 for RFID use in the automotive industry, ISO 10374 for container identification in the logistics sector, or ISO standard 11784 for the marking and identification of livestock.