Know Your RFID Frequency Basics

In 2008 I purchased my first toll road RFID transponder, letting me drive through and pay my toll without stopping at a booth. This was my first real-life exposure to RFID, and it was magical. Back then, all I knew was that RFID stood for “radio frequency identification” and that it exchanged data between a transmitter and receiver using radio waves. That’s enough for a highway driver, but you’ll need more information to use RFID in an industrial automation setting. So here are some basics on what makes up an RFID system and the uses of different radio frequencies.

At a minimum, an RFID system comprises a tag, an antenna, and a processor. Tags, also known as data carriers, can be active or passive. Active tags have a built-in power source, and passive tags are powered by the electromagnetic field emitted by the antenna and are dormant otherwise. Active tags have a much longer range than passive tags. But passive tags are most commonly used in industrial RFID applications due to lower component costs and no maintenance requirements.

Low frequency (LF), high frequency (HF), ultra-high frequency (UHF)

The next big topic is the different frequency ranges used by RFID: low frequency (LF), high frequency (HF), and ultra-high frequency (UHF). What do they mean? LF systems operate at a frequency range of 125…135 kHz, HF systems operate at 13.56 MHz, and UHF systems operate at a frequency range of 840…960 MHz. This tells you that the systems are not compatible with each other and that you must choose the tag, antenna, and processor unit from a single system for it to work properly. This also means that the LF, HF, and UHF systems will not interfere with each other, so you can install different types of RFID systems in a plant without running a risk of interference or crosstalk issues between them or any other radio communications technology.

 

Choosing the correct system frequency?

How do you choose the correct system frequency? The main difference between LF/HF systems and UHF systems is the coupling between the tags and the antenna/processor. LF and HF RFID systems use inductive coupling, where an inductive coil on the antenna head is energized to generate an inductive field. When a tag is present in that inductive field, it will be energized and begin communications back and forth. Using the specifications of the tag and the antenna/processor, it is easy to determine the read/write range or the air gap between the tag and the antenna head.

The downside of using LF/HF RFID technology based on inductive coupling is that the read/write range is relatively short, and it’s dependent on the physical size of the coils in the antenna head and the tag. The bigger the antenna and tag combination, the greater the read/write distance or the air gap between the antenna and the tag. The best LF and HF RFID uses are in close-range part tracking and production control where you need to read/write data to a single tag at a time.

UHF RFID systems use electromagnetic wave coupling to transmit power and data over radio waves between the antenna and the tag. The Federal Communications Commission strictly regulates the power level and frequency range of the radio waves, and there are different frequency range specifications depending on the country or region where the UHF RFID system is being used. In the United States, the frequency is limited to a range between 902 and 928MHz. Europe, China, and Japan have different operating range specifications based on their regulations, so you must select the correct frequency range based on the system’s location.

Using radio waves enables UHF RFID systems to achieve a much greater read/write range than inductive coupling-based RFID systems. UHF RFID read/write distance range varies based on transmission power, environmental interference, and the size of the UHF RFID tag, but can be as large as 6 meters or 20 feet. Environmental interferences such as metal structures or liquids, including human bodies, can deflect or absorb radio waves and significantly impact the performance and reliability of a UHF RFID system. UHF RFID systems are great at detecting multiple tags at greater distances, making them well suited for traceability and intralogistics applications. They are not well suited for single tag detection applications, especially if surrounded by metal structures.

Because of the impact an environment has on UHF signals, it is advisable to conduct a full feasibility study by the vendor of the UHF RFID system before the system solution is purchased to ensure that the system will meet the application requirements. This includes bringing in the equipment needed, such as tags, antennas, processors, and mounting brackets to the point of use to ensure reliable transmission of data between the tag and the antenna and testing the system performance in normal working conditions. Performing a feasibility study reduces the risk of the system not meeting the customer’s expectations or application requirements.

Selecting an industrial RFID system

There are other factors to consider when selecting an industrial RFID system, but this summary is a good place to start:

    • Most industrial RFID applications use passive RFID tags due to their lower component costs and no battery replacement needs.
    • For applications requiring short distance and single tag detection, LF or HF RFID systems are recommended.
    • For applications where long-distance and multi-tag detection is needed, UHF RFID systems are recommended.
    • If you are considering UHF, a feasibility study is highly recommended to ensure that the UHF RFID system will perform as intended and meet your requirements.

Click here to browse our library of Automation Insights blogs related to RFID.

Error-Free Assembly of Medical Components

A SUV and a medical device used in a lab aren’t very similar in their looks, but when it comes to manufacturing them, they have a lot in common. For both, factory automation is used to increase production volume while also making sure that production steps are completed precisely. Read on to learn about some ways that sensors are used in life science manufacturing.

Sensors with switching output

Automation equipment producers are creative builders of specialized machines, as each project differs somehow from previous ones. When it comes to automated processes in the lab and healthcare sectors where objects being processed or assembled are small, miniaturization is required for manufacturing equipment as well.  Weight reduction also plays an important role in this, since objects with a lower mass can be moved quickly with a smaller amount of force. By using light-weight sensors on automated grippers, they can increase the speed of actuator movements.

Conveyor system using photoelectric sensors for object detection

Photoelectric sensors are quite common in automated production because they can detect objects from a distance. Miniaturized photoelectric sensors are more easily placed in a production process that works with small parts. And photoelectric sensors can be used to detect objects that are made of many different types of material.

A common challenge for lab equipment is to detect clear liquids in clear vessels. Click here for a description of how specialized photoelectric sensors face this challenge.

Specialized photoelectric sensors for clear water detection

Image Processing

Within the last several years, camera systems have been used more frequently in the production of lab equipment. They are fast enough for high-speed production processes and support the use of artificial intelligence through interfaces to machine learning systems.

Identification

In any production setting, products, components and materials must be identified and tracked. Both optical identification and RFID technology are suitable for this purpose.

Sample analysis with industrial camera

Optical identification systems use a scanner to read one-dimensional barcodes or two-dimensional data matrix or QR codes and transmit the object information centrally to a database, which then identifies the object. The identification cost per object is pretty low when using a printed label or laser marking on the object.

When data must be stored directly on or with the object itself, often because the data needs to be changed or added to during the production process, RFID (Radio Frequency Identification) is the best choice. Data storage tags come in many different sizes and can store different amounts of data and have other features to meet specific needs. This decentralized data storage has advantages in fast production processes when there is a need for real-time data storage.

Data of RFID tag at pallet are read and written with RFID read/write head and transferred via bus module

There are numerous parallels between automation in the life science sector and general factory automation. While these manufacturing environments both have their own challenges, the primary automation task is the same: find the best sensor for your application requirements. Being able to choose from many types of sensors, with different sizes and characteristics, can make that job a lot easier. For more information about the life sciences industries, visit https://www.balluff.com/en-us/industries/life-science.

Machine Tool Identification with RFID -Automation for Advanced Machining

When most people think of automation in manufacturing the first thing that comes to mind is usually a robot. Without a doubt, robots play an integral part in automating the production process, and let’s face it they are pretty cool. However, there is an often overlooked topic in the automation discussion and that is Automatic Data Collection (ADC), which includes barcode and RFID technology. While it doesn’t carry the “cool factor” quite as well as robotics, RFID has helped automate manufacturing, specifically machining, over the last 30 years.

How is it used?

An RFID tag is placed in the tool holder and stays put for the life of the tool. The tag essentially acts as a mini database that can be read and written to thousands of times.

What type of data is typically written to the tag?

Tool Life, Tool Chain Pocket location, Offset Data, Maintenance Info, etc. Up to 2K of info can be written and read and erased and written again. In addition, this information can be updated on the spot.

What are the benefits of using RFID in Machine Tools?

RFID Improves Quality, Increases Efficiency, and Reduces overall Costs by:

Maximizing Tool and Machine Utilization

  • Precise up-to-date tool life information
  • Accurate transfer of tool offset data
  • Continuous tracking of the tool

Minimizing Human Error

  • Eliminates human data entry
  • Automates transfer of data from presetter to machine
  • Data can be accessed directly on the plant floor as opposed to a database lookup

ToolIDRFID is a tried and true technology that will continue to have a great impact on the machining process. Organizations all over the globe are saving millions every year by utilizing this simple method of collecting and transferring data. Machine tool ID is a no-brainer when quality, efficiency, and productivity matters!

For more information or to learn more visit www.balluff.us.

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

RFID ROI – Don’t forget the payback!

traceability_1Just recently, while visiting a customer wanting to implement an RFID asset tracking solution, it occurred to me that ROI (return-on-investment) should always be the ultimate goal for most uses of RFID. What brought this to mind? It was because we were discussing technology before understanding what the ultimate ROI goal was. I’m sure you could say this was failure from a sales perspective, but I’m sure at some point you have also found yourself caught up in the technology seeming so promising and exciting in terms of its benefits, that you lost track of why you were there in the first place. Also, many times, the technology stage is where equipment suppliers and/or integrators are brought in.

As with most projects of this nature, they get started because someone says something like “why don’t we do XXX, it will save us money, time, trouble, loss or get us in compliance” or all of the above and likely more. But this same thought can get lost going through execution. RFID projects are no exception. Many successful RFID implementations show it can bring large benefits in short and long-term ROI not just in asset tracking, but manufacturing, warehousing, supply chain and so on. But the implementor must always keep track of the ROI goal and be willing to share this with their internal stakeholders, supplier and integration partners to be sure everything stays on track and technology does not take over for technologies sake.

Unfortunately the ROI is not always calculated the same for applications. Typically ROI can simply be measured in time period until the investment is paid back or the money saved over a given period of time. The most simplistic way of calculating payback or ROI is: Cost of Project (calculated at the beginning) / Annual Cash Revenues (expected savings) = Payback Period. Unfortunately the rub comes in when calculating the detail in the two factors. This can be because the cost of the project is not totally encompassing and/or revenue does not take into consideration factors like interest costs or variations in production, for example. As this will ultimately become the measure of successful projects, really understanding ROI is critical.

Factors in Annual Cash Revenues are factors the implementer needs to understand and grasp as the reasons for undertaking a project. These factors will typically involve several aspects of their business, including savings from greater efficiency, lower cost in storage or inventory, less scrap, higher quality standards (less failure returns), compliance benefits, etc. In fact, this part is difficult to encompass here in this forum. But Cost of Project has some factors I can point out. In the example I raised in the beginning, the customer needed to not only address the read/write equipment and tags (including handheld’s), but also the cost of installing all the possible variations in tag types used during manufacture, common database/software needed, bringing distributors and field service on board, integration providers costs (internal also), training needs, software licensing, start-up and support cost, and so on. So in a manufacturing line, it starts with the new equipment, but must include the PLC/database programming, pallet modifications, station installation, spare parts, start-up and training for example. In warehousing, it might include new equipment, loss of facility equipment like forklifts or warehouse area, facility modification like electrical for example, ERP and WMS implementation or integration, commissioning and training.

One thing to consider toward understanding these factors before implementing a total enterprise solution, whether in warehousing, supply chain or manufacturing is to consider a pilot or test/trail program to determine as many factors as possible and test the results before committing to the full investment of the complete project.

So in your next project, remember to include your stakeholders and partners in your end goals, try to encompass all the factors and don’t forget the payback!

To learn more about RFID visit us at www.balluff.us/rfid.

When to use IO-Link RFID

IO-Link logoAt this point it is pretty clear that RFID is a fairly simple identification solution that involves a tag, antenna, and processor. The tag holds the information that is critical to the application. That information could be a very brief identifying number, sometimes called a license plate, and usually consists of 4 to 12 Bytes of data. Or, the application may require the tag to hold all the information about the product being manufactured such as build data, process data, or lineage data. In this case, there are tags with up to 128 Kilobytes of available storage. The scenarios above help to answer the question: “when do I use IO-Link RFID?”

Simply put, IO-Link makes life on the manufacturing floor much easier. It eliminates the mess in the cabinet, it is plug and play, it allows connection to any major controller, etc. etc. etc. So, why not just do away with everything not IO-Link and call it a day? For RFID there is 1 major question that needs to be answered to determine whether or not IO-Link is the right solution: How much data needs to be read from the tag?

IO-link specializes in transferring smaller amounts of data. When required to transfer large amounts the speed is greatly reduced. Here is a very simple way to look at it: IO-Link RFID comes in two different versions- 10Bytes or 32Bytes. The 10 Bytes or 32 Bytes refer to the size of the buffer or container that transfers the data. Imagine this as two semi-trucks carrying a load in a trailer (buffer). Of course, the 32 Byte trailer can carry a larger load (Data) than the 10Byte trailer. Therefore, we can conclude that the 10Byte trailer has to make more trips to carry larger amounts of data. More trips take more time therefore slowing down the process. If there are only 8Bytes of data that need to be read from the tag then the 10Byte version is fine, but if there are 28 bytes then it makes sense to us the 32 Byte version. However, as mentioned above there are applications where the tag may hold up to 8KB, 32KB, or even 128KB of data and IO-Link should not be considered. As a general rule IO-link should not be used to read anything over 96 Bytes due to speed being greatly reduced.

Need For Speed?

As a rule of thumb it takes about .2 seconds for IO-Link RFID readers to read 16Bytes of data and about .5 seconds to read 96Bytes. Reading anything above 96Bytes increases the read time dramatically. As a comparison, the latest and greatest Balluff RFID processor, the BIS V can read 256Bytes of data in about .2 seconds.

Ultimately, the amount of data that needs to be read from the tag and the time required to read that data should be the deciding factors of whether or not IO-Link RFID is right for the job or not.

To learn more about IO-Link visit www.balluff.us

Tracking low-cost assets with RFID tags…Is it worth it?

First, a lesson in Lexicography

Lexi-what!? Don’t be alarmed. This blog is not as boring as it sounds, especially if you are involved in manufacturing. Lexicography is the art of compiling, writing and editing dictionaries. Sounds like a ton of fun, but let’s move quickly to the point to prevent nausea or inducing sleep. Value, according to dictionary.com when used as a noun, is defined as relative worth, merit, or importance. Notice, the lexicographer mentions nothing about cost.

Tracking valuable assets using RFID within the walls of a plant has become common practice for many organizations. Tracking fork trucks, specialized equipment, machinery and other high cost items are a no-brainer. However, experienced users of RFID technology have realized that it is important to know the location of a high cost asset, but it is paramount to know the location of a high value item.

Defining the VALUE of assets (tools, measurement and calibration devices, specialized machines etc.) can be a tricky game. Conversely, it is not difficult to record the cost of an asset on a balance sheet. A tool which has a cost of $50 doesn’t have a VALUE of $50.

Do you really know what your assets are worth? Is your $50 tool worth hundreds, thousands, or even millions? How is that possible? This is fairly straight forward. If that tool is an integral part in the operation of the manufacturing line then every minute that tool is “missing” is a minute of downtime. How much does a minute of downtime cost your company? How much does an hour of downtime cost your company? Does this tool help your final product conform to standards? What is the cost of nonconformance? What are the financial implications of a product recall? These questions need to be addressed when determining whether or not you should track your assets.

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UHF – Under Heavy Fire or Ultra High Frequency? Logistically Speaking…

Logistics personnel across the globe have been trying to find a way to better manage their pallets, bins, totes, and all other types of containers. Returnable Transport Units (RTU’s) have been stored in remote corners of warehouses, storage trailers, or a who-knows-where location only to be overlooked and written off. They are replaced time and time again by brand new units. Life as an RTU is much like that of the relief pitcher. They go ignored until they are needed, then they become the most important element in the operation. On the bright side they do get to hang out with all their buddies just sitting around waiting to be called up from the bull pen, or storage trailer out back. The difference is when the Manger of the baseball team needs a reliever he just picks up the phone and rings the bull pen. When the warehouse manager needs RTU’s he has to go searching remote areas of the facility many times resulting in a wild goose chase, a PO request, and a phone call to purchase more.
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UHF RFID, One Size Fits All! – Really?

With the proliferation of UHF (ultra-high frequency) based RFID in the commercial and consumer markets, UHF has been seen as the mainstay now for many low-cost, long-range RFID applications. And in recent years with the desire for longer range application flexibility in the industrial sector, naturally users want to gravitate toward technologies and products with a proven track record. But can you really take the same products developed and used for the commercial and consumer logistics markets and apply them reliably to industrial applications like asset tracking, EKanban, general manufacturing or logistics?
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Sensor Based Error Proofing – As easy as 1, 2, 3

Error proofing your manufacturing processes can be as easy as 1, 2, 3. You should be able to freely deploy error proofing in all appropriate locations in your plants without concerns regarding costs and long-term support or stability. It all starts by first identifying your trouble spots, then implementing a detection method, and finally establishing a process to handle the discrepancy. Let’s discuss the detection methods using sensors, as well as the process, for handling discrepancies.

By utilizing sensors as opposed to vision systems or other passive approaches, the cost of implementation and maintenance is reduced. With the new generation of low-cost lasers, sensors are now more affordable and easier to implement.  Radio Frequency Identification (RFID) brings new opportunities for handling non-conforming products. By tagging the individual part, assembly, or lot, products can be directed to the appropriate rework or scrap area.

These methods will allow you to implement more error proofing in your manufacturing lines to save thousand of dollars in scrap or rework and avoid the potential for costly containment.

Top 5 questions regarding error proofing…

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