RFID Basics – Gain Key Knowledge to Select the Best Fit System

As digitalization evolves, industrial companies are automating more and more manual processes. Consequently, they transfer paper-based tasks in the field of identification  to digital solutions. One important enabling technology is radio frequency identification (RFID), which uses radio frequency to exchange data between two different entities for the purpose of identification. Since this technology is mature, many companies now trust it to improve their efficiency. Strong arguments for RFID technology include its contactless reading, which makes it wear-free. Plus, it’s maintenance-free and insensitive to dirt.

RFID basics for selecting the best fit system

There are myriad applications for RFID in the manufacturing process, which can be clustered into the following areas:

    • Asset management e.g. tool identification on machine tools or mold management on injection molding machines in plastic processing companies
    • Traceability for work piece tracking in production
    • Access control for safety and security purposes by instructed and authorized experts to ensure that only the right people can access the machine and change parameters, etc.

But not all RFID is the same. It is important to select the system type and components that are best suited for your application.

Frequencies and their best applications

RFID runs on three different frequency bands, each of which has its advantages and disadvantages.

Low Frequency (LF)
LF systems are in the range of 30…300 kHz and are best suited for close range and for difficult conditions, such as metallic surroundings. Therefore, they fit perfectly in tool identification applications, such as in machine tools, Additionally, they are used in livestock and other animal tracking. The semiconductor industry (front end) relies on this frequency (134kHz) as well.

High Frequency (HF)
HF in the range of 3…30 MHz is ideal for parts tracking at close range up to 400 mm. With HF you can process and store larger quantities of data, which is helpful for tracking and tracing workpieces in industrial applications. But companies also use it for production control. It comes along with high data transmission speeds. Accordingly, it accelerates identification processes.

Ultra High Frequency (UHF)
UHF systems in the range of  300 MHz…3 GHz are widely used in intralogistics applications and typically communicate at a range of up to 6 m distance. Importantly, they allow bulk reading of tags.

RFID key components

Every RFID system consists of three components.

    1. RFID tag (data carrier). The data carrier stores all kinds of information. It can be read and/or changed (write) by computers or automation systems. Read/write versions are available in various memory capacities and with various storage mechanisms. RFID tags are usually classified based on their modes of power supply, including:

– Passive data carriers: without power supply
– Active data carriers: with power supply

2. Antenna or Read/Write head. The antenna supplies the RFID tag with power and reads the data. If desired, it can also write new data on it.

3. Processing unit. The processing unit is used for signal processing and preparation. It typically includes an integrated interface for connecting to the controller or the PC system.

RFID systems are designed for some of the toughest environments and address just most identification applications in the plants. To learn more about industrial RFID applications and components visit www.balluff.us/rifd.

UHF making a big impact on manufacturing

RFIDUltra-High Frequency (UHF) RFID is quickly becoming the go-to identification system for flexible manufacturing lines around the world. While it was once considered to be a system designed primarily for distribution centers and retail stores, UHF technology has evolved to meet the rigors of the manufacturing environment.

Not long ago I was in a discussion with one of my customers who had been using RFID for almost 25 years. He was caught in a tough spot because he had an application which required reading tags from as little as six inches away to as far as two feet away. The HF system he had could easily meet his needs for the six inch read range, but reading at two feet away limited him to using UHF. When I explained that, his bewildered look indicated to me he was reluctant to consider UHF as a real option. He went on to explain that about ten years prior he conducted tests in his plant with UHF and found a host of limitations with the technology. His main concern was how the operators’ two-way radios interfered with the UHF operating frequency of 902-928MHz. Having heard this from other manufacturing organizations who were early adopters I knew right away that he wasn’t aware of how the technology has evolved over the last decade.

Frequency hopping has pretty much eliminated interference with other radio signals. In addition to overcoming radio interference, being able to read and write to tags which are mounted on or near metal and liquids has become a reality with recent advancements. These improvements have led to more flexible read ranges which are a requirement in today’s flexible manufacturing applications.

In a nutshell, the demands of flexible manufacturing have spurred advancements in the process as well as the supporting technology. As it applies to identification of parts or pallets in the manufacturing process, the flexibility of UHF RFID enables manufacturers to gain visibility in their process and provides actionable data that is used to make complex business decisions.

You can learn more about the technology in Balluff’s white paper, What Makes RFID Systems Industrial Strength? or by visiting our website at www.balluff.us