Home Internet of Things Aerospace Apparel Energy Defense Health Care Logistics Manufacturing Retail

Ask The Experts Forum

BlogsAsk The Experts ForumWhat Should I Use to Track Thousands of Sewing Machines on a Production Floor?

What Should I Use to Track Thousands of Sewing Machines on a Production Floor?

Posted By RFID Journal, 07.15.2013

What are the differences between Wi-Fi-based real-time location systems and active RFID-based RTLS technology?

—Name withheld

———

W-Fi-based real-time location systems employ active RFID tags that communicate via Wi-Fi access points. You might be able to utilize your existing access points if you have them spread around your production facility, or you may need to deploy additional access point to achieve the location accuracy you require. Active RFID-based RTLS solutions are similar, but instead of communication with Wi-Fi access points, they send signals to antennas located around your premises.

I'm not sure that either is the best option for tracking sewing machines, however. Generally speaking, active tags (including Wi-Fi tags) are fairly large, since they need to house electronics in hard plastic. Larger tags could interfere with production of the machines. Additionally, these tags are expensive—$50 or more. You could recycle them, but an active solution might be expensive. (If your machines are placed on carriers, then tracking those carriers with an active tag might be a good option.)

Typically, when monitoring work-in-process, you would want to know that a specific unit has proceeded from one station to the next. Placing a passive high-frequency (HF) or ultrahigh-frequency (UHF) label inside a sewing machine's housing, as well as reader antennas at each station, could be a cost-effective alternative. This is the solution used by HP Brasil to track printers (see Extracting New Value From Old Printers and Keeping Tabs on Printers), and many other companies have implemented the technology as well.

The best thing to do would be to hire a reliable consultant or systems integrator to evaluate your site, your business processes and the data you need to collect in order to improve your processes. That person could recommend the best type of RFID (or other technology) for your particular needs, and suggest some appropriate solution providers.

—Mark Roberti, Founder and Editor, RFID Journal

USER COMMENTS

WK Chan 2013-07-19 12:43:14 AM
Dear Mark, Thanks very much for your valuable advices. Actually I have been approaching few system integrators, however their answers to my questions are different that I'd like to seek professional advice from you. 1) Choke Point Locating - I plan to use passive RFID and RFID-enabled gate. However I have encountered the below challanges: a) one supplier said that the power of the antenna (gate) is too strong that it has potential risk to human. However, another supplier said it is ok… Below are some information of the antenna we used: - Freq. range: 860-868MHz, 902-928MHz - Max power: 31.5dBm, 39dBm - Antenna is planned to operate 24/7, employees work 8 hours close to the antenna. b) We did a Proof of Concept (POC) but the results were not acceptable. Some machines could not be detected when passing through the gate. We used both on-metal passive RFID and normal passive RFID. (UHF 915 MHz). I am trying to identify the causes of the failure but I am told that only active RFID can guarantee 100% accuracy. 2) RTLS – I also think about using active RFID to keep track the real time location of the machines. However a large number of interrogators is required that make the system very costly. Besides, I am told that we cannot change batteries ourselves and must send the tags back to their factories for replacement every 2 or 3 years. I wonder why we cannot do it ourselves. My questions are: 1) Is there any international safety standard for the power of the antenna used? Does it really have potential risk to our employees? 2) In what areas we can do to improve the accuracy of the choke point locating? 3) Are there any active RFID tags that we can change or recharge batteries ourselves? 4) For RTLS, which technology (WiFi-based vs. Active RFID-based) is more mature and reliable? Looking forward to hearing your professional advices. Thanks very much CWK
Mark Roberti 2013-07-22 10:55:56 AM
Here are my answers: 1) Is there any international safety standard for the power of the antenna used? Does it really have potential risk to our employees? There is no international standard for the safe use of RFID systems. Research done at the University of Texas at Arlington found that an RFID reader located 10 cm (3.9 inches) from the human head could cause health issues (see Can RFID Be Harmful to the Human Body? - http://www.rfidjournal.com/blogs/experts/entry?5001). Some reader manufacturers suggest keeping antenas at least 22 cm away from employees or the public (see Analyst Viewpoint: Take Appropriate RFID Precautions - http://www.rfidjournal.com/articles/view?6703). For periods of prolonged exposure, I would err on the side of caution and keep employees several feet, at least, from a reader antenna that will be operating constantly. 2) In what areas we can do to improve the accuracy of the choke point locating? It is difficult to know the problem without having a lot more information, but in general, I would say that it should be possible to get 100 percent read accuracy of objects going through a portal, unless they are on pallets and you are trying to read tags on items in the center of the pallet. Carrier has achieved 100 percent read accuracy in its production facility and most of its products and many components are metal (see Carrier Takes Manufacturing to a Higher Level - http://www.rfidjournal.com/articles/view?10718). This is an issue of choosing the right tag, having the right tag location on the sewing machine and having the portals configured properly. 3) Are there any active RFID tags that we can change or recharge batteries ourselves? I am not aware of an active system where you can change the batteries yourself. If any readers are, please post information below 4) For RTLS, which technology (Wi-Fi-based vs. Active RFID-based) is more mature and reliable? There are a wide variety of active RFID systems on the market. Most of them are very good and can read tags with 100 percent accuracy because the tags are broadcasting their information. The bigger question with active systems (including Wi-Fi-based active RFID systems) is their location accuracy. How accurate they are can depend on both the method of calculating location as well as proper deployment of the system. I think you should be able to accomplish your goals with a passive system, but you will need to find the right systems integrator.

Login and post your comment!

Not a member?

Signup for an account now to access all of the features of RFIDJournal.com!

Next Post
Can an RFID Tag Be Used to Light Up an L...
Previous Post
What Is the State-of-the-Art in Triangul...
PREMIUM CONTENT
Case Studies Features Best Practices How-Tos
RFID JOURNAL EVENTS
Live Events Virtual Events Webinars
ASK THE EXPERTS
Simply enter a question for our experts.
TAKE THE POLL
JOIN THE CONVERSATION ON TWITTER
Loading
RFID Journal LIVE! RFID in Health Care LIVE! LatAm LIVE! Brasil LIVE! Europe RFID Connect Virtual Events RFID Journal Awards Webinars Presentations
© Copyright 2002-2016 RFID Journal LLC.
Powered By: Haycco