RFID Replaces Bar Codes for Efficient Asset Tracking

Bar code technology has been around for many years and is a tried and true means for tracking asset and product movement, but it has its limitations. For example, a bar code reader must have an unobstructed view of the bar code to effectively scan. And the bar code label cannot be damaged, or it is then unreadable by the scanner.

In more recent years, additional RFID technologies have been more readily available for use to accomplish the same task but with fewer limitations. Using RFD, a scanner may be able to read tags that are blocked by other things and not visible to the naked eye. UHF RFID can scan multiple tags at the same time in a single scan, whereas most bar codes need to be scanned individually. This, therefore, increases efficiency and reduces the time required to perform the scans.

Then, of course, there is the human factor. RFID can help eliminate mistakes caused by human error. Most bar code scanning is done with hand scanners held by workers since the scanner has to be in the exact position to see the bar code to get a good scan. While manual/hand-held scanning can be done using RFID, most times a fixed scanner can be used as long as the position of the RFID tag can be guaranteed within certain tolerances. These tolerances are much greater than with a bar code scanner.

With the advent of inexpensive consumable RFID labels, the ease and cost of transitioning to RFID technology has become more feasible for manufacturers and end users. These labels can be purchased for pennies each in rolls of several thousand at a time.

It should be noted that several companies now produce printers that can actually code the information on a RFID label tag while also printing data, including bar codes, on these label tags so you have the best of both worlds. Tags can be scanned automatically and data that can be read by the human eye as well as a bar code scanner.

Some companies have expressed concern about the usage of RFID in different countries due to local regulations regarding the frequencies of radio waves causing interferences.

This is not an issue for HF  and UHF technology. HF is an ISO standard (ISO 15693) technology so it applies to most everywhere. For UHF, which is more likely to be used due to the ability to scan at a distance and scan multiple tags at the same time, the only caveat is that different areas of the world allow scanners to only operate in certain frequencies. This is overcome by the fact that almost all UHF tags that I have encountered are what are called global tags.

This means these tags can be used in any of the global frequency ranges of UHF signals. For example, in the North America, the FCC restricts the frequency range for UHF RFID scanners to 902-928 MHz, whereas MIC in Japan restricts them to 952-954 MHz, ETSI EN 300-220 in Europe restricts them to 865-868 MHz, and DOT in India restricts them to 865-867 MHz. These global tags can be used in any of these ranges as they work from 860 to 960 MHz.

On the subject of UHF, it should be mentioned that in addition to the frequency ranges restricted by various part of the world, maximum antenna power is also locally restricted.

For more information on RFID for asset tracking, visit https://www.balluff.com/local/us/products/product-overview/rfid/

 

Turning Big Data into Actionable Data

While RFID technology has been available for almost seventy years, the last decade has seen widespread acceptance, specifically in automated manufacturing. Deployed for common applications like automatic data transfer in machining operations, quality control in production, logistics traceability and inventory control, RFID has played a major role in the evolution of data collection and handling. With this evolution has come massive amounts of data that can ultimately hold the key to process improvement, quality assurance and regulatory compliance. However, the challenge many organizations face today is how to turn all that data into actionable data.

Prominent industry buzzwords like Industry 4.0 and the Industrial Internet of Things (IIOT) once seemed like distant concepts conjured up by a marketing team far away from the actual plant floor, but those buzzwords are the result of manufacturing organizations around the globe identifying the need for better visibility into their operations. Automation hardware and the infrastructure that supports it has advanced rapidly due to this request, but software that turns raw data into actionable data is still very much in demand. This software needs to provide interactive feedback in the form of reporting, dashboards, and real time indicators.

The response to the demand will bring vendors from other industries and start-ups, while a handful of familiar players in automation will step up to the challenge. Competition keeps us all on our toes, but the key to filling the software gap in the plant is partnering with a vendor who understands the needs on the plant floor. So, how do you separate the pretenders from the contenders? I compiled a check list to help.

Does the prospective vendor have:

  • A firm understanding that down time and scrap need to be reduced or eliminated?
  • A core competency in automation for the plant floor?
  • Smart hardware devices like RFID and condition monitoring sensors?
  • A system solution that can collect, analyze, and transport data from the device to the cloud?
  • A user-friendly interface that allows interaction with mobile devices like tablets and phones?
  • The capability to provide customized reports to meet the needs of your organization?
  • A great industry reputation for quality and dependability?
  • A chain of support for pre-sales, installation, and post-sales support?
  • Examples of successful system deployments?
  • The willingness to develop or modify current devices to address your specific needs?

If you can check the box for all of these, it is a safe bet you are in good hands. Otherwise, you’re rolling the dice.

Which RFID Technology is Best for Your Traceability Application?

There are a lot of articles on using RFID for traceability, but it’s hard to know where to begin. Examples of traceability include locating an important asset like a specific mold that is required to run a machine or verifying a specific bin of material required to run production. Spending time looking for these important assets leads to lost time and production delays. RFID can help but understanding the different RFID capabilities will narrow down the type of RFID that is required.

Not all RFID technology is the same. Each RFID technology operates differently and is categorized by the frequency band of the radio spectrum, such as low frequency, high frequency and ultra-high frequency. In low and high frequency RFID, the read range between RFID tag and reader antenna is measured in millimeters and inches. The read range on ultra-high frequency (UHF) RFID technology can range from one meter to 100 meters. Typically, inventory traceability is done using ultra-high frequency band of the radio frequency spectrum, due to the need to read the asset at a further distance so it does not interfere with the production flow. Also, there are cases where there needs to be a reading of multiple tags in an area at the same time to determine where an asset is located. UHF RFID technology allows for simultaneous reading of multiple RFID tags from a single antenna reader.

There are two types of UHF RFID, passive and active.  Passive UHF RFID means that the RFID tags themselves have no additional power source. The UHF reader antenna sends out an electromagnetic wave field, and the RFID tags within the electromagnetic field have an internal antenna that receives the energy which activates the integrated circuit inside the tag to reflect the signals back to start communicating. The read distance between the passive RFID tag and antenna reader is determined by several factors, such as the size of the electromagnetic wave field generated out of the reader antenna and the size of the receiver antenna on the RFID tag. Typical read ranges on passive UHF systems can be anywhere from one to 12 meters, where the larger the power and RFID tag, the longer the range.

Active UHF RFID systems do not require the tag to reflect signals back to communicate because the active RFID tag has its own transmitter and internal battery source. Because of this, with active UFH RFID you can get read ranges of up to 100 meters. There are active tags which wake up and communicate when they receive a radio signal from a reader antenna, while others are beacons which emit a signal at a pre-set interval. Beacon active tags can locate in real time the location of the asset that the RFID tag is attached to. However, a downfall to active RFID tags is the battery life on the tag. If the battery is dead, then the asset will no longer be visible.

Figure 1

Once the strengths and weaknesses of each type of UHF RFID system is known, it’s easier to work with the constraints of the system. For example, the application in Figure 1 shows a reader antenna for reading bins of material placed a few feet away so that its’ not in the way of production. A passive UHF RFID system will work in this case, due to the distance between the antenna and the RFID tag on the bin a few feet away. There is no need to worry about battery life on the passive RFID tag.

Figure 2

If the exact location of a production mold is required in a large facility, then using an active UHF RFID system is likely a better fit. Incorporating an active RFID tag that sends out a beacon at a fixed interval to a data center ensures the location of all assets are always known. With this setup, the exact location of the mold can be found at any time in the facility.

Examining the different types of RFID technology can help determine the correct one to use in a traceability application. This includes analyzing the pros and cons of each technology and seeing which one is the best fit for the application.

The Right Mix of Products for Recipe-Driven Machine Change Over

The filling of medical vials requires flexible automation equipment that can adapt to different vial sizes, colors and capping types. People are often deployed to make those equipment changes, which is also known as a recipe change. But by nature, people are inconsistent, and that inconsistency will cause errors and delay during change over.

Here’s a simple recipe to deliver consistency through operator-guided/verified recipe change. The following ingredients provide a solid recipe-driven change over:

Incoming Components: Barcode

Fixed mount and hand-held barcode scanners at the point-of-loading ensure correct parts are loaded.

Change Parts: RFID

Any machine part that must be replaced during a changeover can have a simple RFID tag installed. A read head reads the tag in ensure it’s the correct part.

Feed Systems: Position Measurement

Some feed systems require only millimeters of adjustment. Position sensor ensure the feed system is set to the correct recipe and is ready to run.

Conveyors Size Change: Rotary Position Indicator

Guide rails and larger sections are adjusted with the use of hand cranks. Digital position indicators show the intended position based on the recipes. The operators adjust to the desired position and then acknowledgment is sent to the control system.

Vial Detection: Array Sensor

Sensor arrays can capture more information, even with the vial variations. In addition to vial presence detection, the size of the vial and stopper/cap is verified as well. No physical changes are required. The recipe will dictate the sensor values required for the vial type.

Final Inspection: Vision

For label placement and defect detection, vision is the go-to product. The recipe will call up the label parameters to be verified.

Traceability: Vision

Often used in conjunction with final inspection, traceability requires capturing the barcode data from the final vials. There are often multiple 1D and 2D barcodes that must be read. A powerful vision system with a larger field of view is ideal for the changing recipes.

All of these ingredients are best when tied together with IO-Link. This ensures easy implantation with class-leading products. With all these ingredients, it has never been easier to implement operator-guided/verified size change.

How RFID Can Error-Proof Appliance Assembly

Today, appliance manufactures are using RFID more frequently for error proofing applications and quality control processes.

Whether the appliance assembly process is automatic or semiautomatic, error-proofing processes using RFID are as important as the overall assembly processes. Now, RFID systems can be used to tell a PLC how well things are moving, and if the products and parts are within spec. This information is provided as an integral part of each step in the manufacturing process.

RFID systems installed throughout the manufacturing process provide a way of tracking not only what has happened, but what has gone right. RFID records where something has gone wrong, and what needs to be done to correct the problem.

Appliance manufacturers often need to assemble different product versions on the same production line. The important features of each part must be identified, tracked and communicated to the control system. This is most effectively done with an RFID system that stores build data on a small RFID tag attached to a build pallet. Before assembly begins, the RFID tag is loaded with the information that will instruct all downstream processes the correct parts that need to be installed.

Each part that goes into the appliance also has a RFID tag attached to it. As the build pallet moves down the assembly conveyor to each station, the tag on the build pallet is read to determine what assembly and error proofing steps are required. Often, this is displayed on an HMI for the operator. If the assembly requires testing, the results of those tests can be loaded into the data carrier for subsequent archiving. The operator scans the tag on each part as it is being installed. That data is then written to the tag on the build pallet. For example, in the washing machine assembly process, the washing machine body sits on the build pallet, and as it moves from station to station, the operators install different components like electronic boards, wiring harnesses, and motors. As each one of these components is installed, its RFID tag is scanned to make sure it is the correct part. If they install the wrong part, the HMI will signal the error.

RFID technology can also be used to reduce errors in the rework process. RFID tags, located on either on the assembly or the pallet, store information on what has been done to the appliance and what needs to be done. When an unacceptable subassembly reaches the rework area, the RFID tag provides details for the operator on what needs to be corrected. At the same time, the tag can signal a controller to configure sensors and tools, such as torque wrenches, to perform the corrective operations.

These are just a few examples of how appliance manufactures are using RFID for error proofing.

For more information, visit https://www.balluff.com/local/us/products/product-overview/rfid/.

Be Driven by Data and Decrease Downtime

Being “driven by data” is simply the act of making decisions based on real data instead of guessing or basing them on theoretical outcomes. Why one should do that, especially in manufacturing operations, is obvious. How it is done is not always so clear.

Here is how you can use a sensor, indicator light, and RFID to provide feedback that drives overall quality and efficiency.

 

Machine Condition Monitoring

You’ve heard the saying, “if it ain’t broke, don’t fix it.” However, broken machines cause downtime. What if there was a way to know when a machine is getting ready to fail, and you could fix it before it caused downtime? You can do that now!

The two main types of data measured in manufacturing applications are temperature and vibration. A sudden or gradual increase in either of these is typically an indicator that something is going wrong. Just having access to that data won’t stop the machine from failing, though. Combined with an indicator light and RFID, the sensor can provide real-time feedback to the operator, and the event can be documented on the RFID tag. The machine can then be adjusted or repaired during a planned maintenance period.

Managing Quality – A machine on its way to failure can produce parts that don’t meet quality standards. Fixing the problem before it affects production prevents scrap and rework and ensures the customer is getting a product with the quality they expect.

Managing Efficiency– Unplanned downtime costs thousands of dollars per minute in some industries. The time and resources required to deal with a failed machine far exceed the cost of the entire system designed to produce an early warning, provide indication, and document the event.

Quality and efficiency are the difference makers in manufacturing. That is, whoever makes the highest quality products most efficiently usually has the most profitable and sustainable business. Again, why is obvious, but how is the challenge. Hopefully, you can use the above data to make higher quality products more efficiently.

 

More to come! Here are the data-driven topics I will cover in my next blogs:

  • Part inspection and data collection for work in process
  • Using data to manage molds, dies, and machine tools

RFID Minimizes Errors, Downtime During Format Change

Today’s consumer packaged goods (CPG) market is driving the need for greater agility and flexibility in packaging machinery. Shorter, more customized runs create more frequent machine changeover. Consequently, reducing planned and unplanned downtime at changeover is one of the key challenges CPG companies are working to improve.

In an earlier post, I discussed operator guided changeover for reducing time and errors associated with parts that must be repositioned during format change.

In this post, I will discuss how machine builders and end users are realizing the benefits of automated identification and validation of mechanical change parts.

In certain machines, there are parts that must be changed as part of a format change procedure. For example, cartoning machines could have 20-30 change parts that must be removed and replaced during this procedure.

This can be a time consuming and error-prone process. Operators can forget to change a part or install the wrong part, which causes downtime during the startup process while the error is located and corrected. In the worst scenarios, machines can crash if incorrect parts are left in the machine causing machine damage and significant additional downtime.

To prevent these mistakes, CPG companies have embraced RFID as a way to identify change parts and validate that the correct parts have been installed in the machine prior to startup. By doing so, these companies have reduced downtime that can be caused by mistakes. It has also helped them train new operators on changeover procedures as the risk of making a mistake is significantly reduced.

Selecting the correct system

When looking to add RFID for change part validation, the number of change parts that need to be identified and validated is a key consideration. RFID operating on the 13.56 MHz (HF) frequency has proven to be very reliable in these applications. The read range between a read head and tag is virtually guaranteed in a proper installation. However, a read head can read only a single tag, so an installation could need a high number of read heads on a machine with a lot of change parts.

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It is also possible to use the 900 MHz (UHF) frequency for change part ID. This allows a single head to read multiple tags at once. This can be more challenging to implement, as UHF is more susceptible to environmental factors when determining read range and guaranteeing consistent readability. With testing and planning, UHF has been successfully and reliably implemented on packaging machines.

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Available mounting space and environmental conditions should also be taken into consideration when selecting the correct devices. RFID readers and tags with enhanced IP ratings are available for washdown harsh environmental conditions. Additionally, there are a wide range of RFID read head and tag form factors and sizes to accommodate different sized machines and change parts.

 

 

Manufacturers Track Goods, Reduce Errors, Decrease Workload with RFID

More and more, retailer sellers are starting to require that manufacturers place RFID tags on their products before they leave the production facility and are shipped to those retail locations. From high-end electronics all the way down to socks and underwear are being tagged.

These tags are normally supplied by the retailer or through a contracted third party. Typically disposable UHF paper tags, they are only printed with a TID number and a unique EPC that may or may not correspond to the UPC and barcode that was used in the past. Most cases I have seen require that the UPC and a barcode be printed on these RFID tags so there is information available to the human eye and a barcode scanner when used.

While this is being asked for by the retailers, manufacturers can use these tags to their own advantage to track what products are going out to their shipping departments and in what quantities. This eliminates human error in the tracking process, something that has been a problem in the past, while also reducing workload as boxes of finished goods no longer must be opened, counted and inspected for accuracy.

A well-designed RFID portal for these items to pass through can scan for quantities and variances in types of items in boxes as they pass through the portal. Boxes that do not pass the scan criteria are then directed off to another area for rework and reevaluation. Using human inspection for just the boxes that do not pass the RFID scan greatly reduces the labor effort and expedites the shipping process.

I recently assisted with a manufacturer in the garment industry who was having to tag his garments for a major retailer with RFID tags that had the UPC and a barcode printed on them. The tags were supplied through the retailer and the EPCs on the tags were quite different then the UPC numbers printed on them.

The manufacturer wanted to know how many garments of each type were in each box. Testing showed that this could be done by creating a check point on his conveyor system and placing UHF RFID antennas in appropriate locations to ensure that all the garments in the box were detected and identified.

In this case, the manufacturer wanted was a simple stand-alone system that would display a count of different types of garments. An operator reviewed the results on a display and decided based on the results whether to accept the box and let the conveyor forward it to shipping or reject it and divert it to another conveyor line for inspection and adjustment.

While this system proved to be relatively simple and inexpensive, it satisfied the desires of the manufacturer. It is, however, possible to connect an RFID inspection station to a manufacturing information system that would know what to expect in each box and could automatically accept or reject boxes based on the results of the scans without human intervention and/or human error.

Palletized Automation with Inductive Coupling

RFID is an excellent way to track material on a pallet through a warehouse. A data tag is placed on the pallet and is read by a read/write head when it comes in range. Commonly used to identify when the pallet goes through the different stages of its scheduled process, RFID provides an easy way to know where material is throughout a process and learn how long it takes for product to go through each stage. But what if you need I/O on the pallet itself or an interchangeable end-of-arm tool?

Inductive Coupling

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Inductive coupling delivers reliable transmission of data without contact. It is the same technology used to charge a cell phone wirelessly. There is a base and a remote, and when they are aligned within a certain distance, power and signal can be transferred between them as if it was a standard wire connection.

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When a robot is changing end-of-arm tooling, inductive couplers can be used to power the end of arm tool without the worry of the maintenance that comes with a physical connection wearing out over time.

For another example of how inductive couplers can be used in a process like this, let’s say your process requires a robot to place parts on a metal product and weld them together. You want I/O on the pallet to tell the robot that the parts are in the right place before it welds them to the product. This requires the sensors to be powered on the pallet while also communicating back to the robot. Inductive couplers are a great solution because by communicating over an air gap, they do not need to be connected and disconnected when the pallet arrives or leaves the station. When the pallet comes into the station, the base and remote align, and all the I/O on the pallet is powered and can communicate to the robot so it can perform the task.

Additionally, Inductive couplers can act as a unique identifier, much like an RFID system. For example,  when a pallet filled with product A comes within range of the robot, the base and remote align telling the robot to perform action A. Conversely, when a pallet loaded with product B comes into range, the robot communicates with the pallet and knows to perform a different task. This allows multiple products to go down the same line without as much changeover, thereby reducing errors and downtime.

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.