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.

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How Industrial RFID Can Reduce Downtime in Your Stamping Department

The appliance industry is growing at record rates. The increase in consumer demand for new appliances is at an all-time high and is outpacing current supply. Appliance manufacturers are increasing production to catch up with this demand. This makes the costs associated with downtime even higher than normal. But using industrial RFID can allow you to reduce downtime in your stamping departments and keep production moving.

Most major household appliance manufacturers have large stamping departments as part of their manufacturing process. I like to think of the stamping department as the heart of the manufacturing plant. If you have ever been in a stamping department while they are stamping out metal parts, then you understand. The thumping and vibration of the press at work is what feeds the rest of the plant.  I was in a plant a few weeks ago meeting with an engineer in the final assembly area. It was oddly quiet in that area, so I asked what was going on. He said they’d sent everyone home early because one of their major press lines went down unexpectedly. Every department got sent home because they did not have the pieces and parts needed to make the final product. That is how critical the stamping departments are at these facilities.

In past years, this wasn’t as critical, because they had an inventory of parts and finished product. But the increase in demand over the last two years depleted that inventory. They need ways to modernize the press shop, including implementing smarter products like devices with Industry 4.0 capabilities to get real-time data on the equipment for things like analytics, OEE (Overall Equipment Effectiveness), preventative maintenance, downtime, and more error proofing applications.

Implementing Industrial RFID

One of the first solutions many appliance manufacturers implement in the press department is traceability using industrial RFID technology. Traceability is typically used to document and track different steps in a process chain to help reduce the costs associated with non-conformance issues. This information is critical when a company needs to provide information for proactive product recalls, regulatory compliance, and quality standards. In stamping departments, industrial RFID is often used for applications like asset tracking, machine access control, and die identification. Die ID is not only used to identify which die is present, but it can also be tied back to the main press control system to make sure the correct job is loaded.

need for RFID in appliance stamping
This shows an outdated manual method using papers that are easily lost or destroyed.
appliance stamping can be improved by RFID
This image shows an identification painted on a die, which can be easily destroyed.

Traditionally, most companies have a die number either painted on the die or they have a piece of paper with the job set up attached to the die. I cannot tell you how many times I have seen these pieces of paper on the floor. Press departments are pretty nasty environments, so these pieces of paper get messed up pretty quickly. And the dies take a beating, so painted numbers can easily get rubbed or scratched off.

Implementing RFID for die ID is a simple and affordable solution to this problem. First, you would attach an RFID tag with all of the information about the job to each die. You could also write maintenance information about the die to this tag, such as when the die was last worked on, who last worked on it, or process information like how many parts have been made on this die.
Next, you need to place an antenna. Most people mount the antenna to one of the columns of the press where the tag would pass in front of it as it is getting loaded into the die. The antenna would be tied back to a processor or IO-Link master if using IO-Link. The processor or IO-Link master would communicate with the main press control system. As the die is set in the press, the antenna reads the tag and tells the main control system which die is in place and what job to load.

In a stamping department you might find several large presses. Each press will have multiple dies that are associated with each press. Each die is set up to form a particular part. It is unique to the part it is forming and has its own job, or recipe, programmed in the main press control system. Many major stamping departments still use manual operator entry for set up and to identify which tools are in the press. But operators are human, so it is very easy to punch in the wrong number, which is why RFID is a good, automated solution.

In conclusion

When I talk with people in stamping departments, they tell me one of the main reasons a crash occurs is because information was entered incorrectly by the operator during set up. Crashes can be expensive to repair because of the damage to the tooling or press, but also because of the downtime associated. Establishing a good die setup process is critical to a stamping department’s success and implementing RFID can eliminate many of these issues.

Not All RFID is Created Equal: Is Yours Built for an Industrial Environment?

The retail environments where products are sold look nothing like the industrial environments where they are produced (think of the difference between a new car dealership and an automotive manufacturing plant). Yet the same RFID products developed for retail stores and their supply chain operations are still marketed to manufacturers for production operations. These products may work fine in warehouses, but that does not necessarily qualify them as industrial grade.

IO-Link_RFID

So what are the differences between retail and industrial RFID?

Production environments often require a level of ruggedness, performance, and connectivity that only purpose-built industrial equipment can reliably satisfy. For example, general-purpose RFID equipment may have the physical Ethernet port needed to connect to a PC or server, but will not support EtherNet/IP, Profinet or other industrial protocols that run on PLCs and other industrial automation control equipment. Many retail grade readers need to be supported with an additional protocol conversion, which can require external hardware and slow system performance, and adds to implementation time, difficulty, and expense.

When evaluating RFID equipment, it is essential to make the distinction between what is possible for use in the environment and what is optimal and, therefore, more reliable. There are three fundamental qualities to consider that can determine if RFID systems will perform reliably in demanding production environments:

  • Will the RFID system integrate seamlessly with industrial control systems?
  • Will it provide the reliability and speed that production and their information systems tied in require?
  • Can it maintain uptime and performance long term – will it last on the production line?

RFID is often marketed as a “solution,” however in manufacturing operations, it is almost always used as a supporting technology to provide data and visibility to the MES, ERP, e-Kanban, robotics, asset tracking, material handling, quality control and other systems that run in production facilities. Failure to accurately provide data to these systems at the reliability and speed levels they require eliminates the value of using RFID.

The physical environments in industrial and supply chain settings cause RFID technology to perform differently. Tag density can be a consideration for industrial RFID users like retail, but an industrial environment has much more challenging and powerful potential interference sources, for example, the presence of metal found in most industrial products and environments.

When determining whether RFID products are suitable for a specific environment, it is important to look beyond published marketing hype and misleading specifications. Consider the design and construction of the product and how it could be affected by various work processes. Whenever possible, you should test the products where they will be used rather than in a lab or demonstration area, because the actual work location has interference and environmental conditions that may be overlooked and impossible to duplicate elsewhere.

The key attributes that differentiate industrial RFID equipment from supply chain-oriented alternatives include:

  • Native support for industrial protocols;
  • High tag read reliability and the ability to continuously operate at speeds that won’t slow production systems;
  • Durable housing with secure connectors with IP65 or better rating and relevant certifications for shock, vibration and temperature resistance;
  • The ability to support multiple RFID technologies and supporting devices as needed, including sensors, PLCs, IO-Link, and other industrial automation equipment.

Compromising on any of these criteria will likely result in unnecessary implementation time, support, and replacement costs and increase the risk for system failure.

Optimized Utilization and Increased Transparency with RFID

Unscheduled downtimes in production due to worn out or unserviced molds in machines can cause high costs and are a well-known problem for a lot of companies. In order to prevent these issues and optimize the use of their injection molds, a Swiss chocolate mold producer installed a predictive maintenance system via industrial RFID technology.

Maintaining oversight during frequent mold changes with RFID

Complex and expensive injection molds are typically used in manufacturing parts. Due to wear and contamination, they require regular cleaning, care and maintenance. The regularity often depends on handwritten records in a molds log-book, post-its or on the experience of the employees. In more modern companies, databases or excel sheets may be used to store this information. Regardless of the method, real-world experience shows that manual recording is often prone to errors. Maintenance and inspection are often only carried out if a mold malfunctions, when it tends to be too late.

Poured chocolate molds endure wear and need regular maintenance

Poured chocolate molds, that are used in continuous operation on the production lines of chocolate manufacturers, are known worldwide for their perfection and durability. In most cases, they are made in comparatively small batch sizes of 1500 to 2000 units. For this reason, the injection molds have a modular structure. The base is a master mold with exchangeable inserts which leads to quick and frequent mold change cycles. Additionally, there are certain things that require increased maintenance, like replacing hoses, lines or connecting components, that involve removing the master mold. This is why it is especially important to keep track of how many times a master mold has been used. A control system via industrial RFID technology can be installed to solve this problem.

Continue reading “Optimized Utilization and Increased Transparency with RFID”

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

How to Make Plant-based Assets Smarter

 

traceability…add RFID

Pallets, bins, shipping containers, machine tools, hand tools, calibration equipment, neumatic and hydraulic cylinders, etc, etc, etc can all be given some level of intelligence which would make life easier within the plant. Plant-based assets are truly assets because they make our job easier or they allow us to be more efficient. When workers are efficient they are more productive.

Really it all comes down to the questions that we need answered. Here are a few that I have run into in a plant:
Where are all of my pallets and shipping containers?
How much longer can I use this machine tool before the tolerances are out of range?
Has this gauge been calibrated? when? by whom? what are the parameters?
I need to re-order this part or order spare parts and the manufacturer information has been worn off. What is the serial number, when was this part manufactured, what is the location of this asset within the plant?

Ultimately, if your assets can answer a few questions your life becomes a little less complex. All of the answers are simply written to the RFID tag and when you have a question you can read the information from the tag with an RFID reader, sometimes called an interrogator for obvious reasons. It’s that simple.

For more information on RFID as a solution visit our website at www.balluff.us/rfid

“Team” Spells Success In Traceability

If you’ve ever considered a traceability project, like asset tracking for instance, you’ve probably also done some homework into the different technological ways to implement it, from barcoding to using RFID (radio frequency identification). And possibly, while doing that research, you may have seen some presentations or read some articles or whitepapers that have talked about the “team” of stakeholders required to implement these projects, especially if involving the scale required for a facility, or even multiple facilities. Well if you’re a manager reading this and involved with such an endeavor, I’m writing to tell you, take this stakeholder team thing seriously.

In many respects, there are rational fears in getting a stakeholder team together in the early stages of these projects, like the conceptualization stage for example. These fears include: Blowing the project out of proportion; Creating mission creep; Even derailing the project with the others self-interests. Again, all can be valid and even come true to a certain extent, but the reality is that most, if not all of the time, these same stakeholders will also identify the potential opportunities and pitfalls that will either help build the REAL ROI case, and/or help prevent the unseen wall that will prevent success.

These stakeholders can range from operational management (warehouse to manufacturing, depending on the target), IT, financial, quality, and engineering, just to get the ball rolling. You must always be careful of allowing the project to slip into “decision by committee”, so hold the reins and have the project lead firm in hand. But by bringing their input, you stand to satisfy not only your goal, but likely the shared goals they also have, validating and strengthening the real ROI that will likely exist if traceability is the requirement. You will also likely find that along the way you will bring improvements and efficiencies that will benefit the broader organization as a whole.

Once you’ve established the goal and the real ROI, reinforced by the stakeholder’s inputs, that is the time to bring in the technology pieces to see what best will solve that goal. This is many times were the first mistake can be made. The technology suppliers are brought in too soon and the project becomes technology weighted and a direction assumed before a true understanding of the benefits and goals of the organization are understood. Considering a project manager before bringing in the technology piece is also a great way to be ready when this time comes. When you’re ready for this stage, this will typically involve bringing in the vendors, integrators and so forth. And guess what, I’m certain you’ll find this part so much easier and faster to deal with, and with greater clarity. If you have that clear picture from your team when you bring in your solution providers, you will find the choices and their costs more realistic, and have a better picture of the feasibility of what your organization can implement and support.

Not to kill the thought with a sports analogy, but a team united and pulling for the same goal in the same direction will always win the game, versus each player looking out for just their own goals. So get your team together and enjoy the sweet taste of ROI success all around.

For more information on Traceability visit www.balluff.us/traceability.

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.

Customization of RFID tag holders and mounting accessories

Does your RFID application require a customized tag holder? What about special brackets for read/write heads and processors? Don’t have the bandwidth to design the mounting hardware required for your unique application? The Balluff Customizing Group can help! If you are implementing the BIS C, BIS L, BIS M or BIS U RFID systems we will make sure you get the performance your application demands.

For several years the Balluff Customizing Group has been working directly with engineers and maintenance personal to provide design and development services for RFID mechanical accessories. The process is streamlined and very straight forward. Please contact Balluff’s Technical Support Professionals to discuss your RFID application.

Here are a few recent examples of RFID projects in the Customizing Group:

1) RFID Pistol Grip Read/Write Head for BIS M data carriers. The modular design can be used with M12, M18 and M30 tubular read/write heads for logistics tracking of incoming and outgoing shipments.

PistolGrip

2) Keyfob with embedded BIS C data carrier. Individual access codes are programmed to the tags allowing only authorized personnel to enter restricted areas.

Keyfob Keyfob2

3) BIS M read/write data carriers embedded in stainless steel NPT plug for Production Tracking.

DataCarrier

RFID – Keep it Simple!

traceabilityMost of us drive an automobile and use a PC daily. However, very few of us could accurately describe the intricate details of how each of those work. They help us get to work and help us do our work. There is not a need for us to know and understand the algorithm that allows us to compose and save an excel spread sheet. As well, there is not much use in knowing the coefficient of friction when using snow tires compared to standard tires. While those factors play a major role in the tools we use every day, we do not necessarily need to be an expert or scientist to reap the benefits.

Much like a car or PC, RFID systems enable us to be more efficient and productive. Specifically, RFID systems in manufacturing enable full visibility into the process. RFID technology provides actionable data to an organization. Having access to actionable data allows an organization to make critical business decisions with a great degree of confidence. Essentially, it takes the guess work out of the process.

So, how does it work? Very simply, a reader reads the information that has been written to the memory of a tag. Yes, it is that simple.

Check out this webex sponsored by SME. This is a very basic introduction to RFID and how it is used in manufacturing.
https://smeweb.webex.com/smeweb/lsr.php?RCID=c517f86066227766f9e36668c2325aa8