POSCO, one of the world's largest steelmakers, has implemented a proprietary RFID-based logistics solution to track and trace multi-ton metal coil products from manufacturing through customer delivery. The automated solution is designed to improve the accuracy and efficiency of key operational processes.
Implementing RFID technology in steel mills poses unique challenges, as the pervasive metal environment interferes with RF signal readability. POSCO used its experience implementing a RFID-based worker safety program in 2009 to design its own logistics system and ensure it integrated seamlessly with its existing manufacturing systems. The company is using modified UPM DogBone UHF tags that have two antennas and are applied upright inside heavy metal coils tags as flag tags, perpendicularly to the items' curved surfaces.
Metal coils are tagged during the packaging process, and items are read when they are moved by cranes to the warehouse, during storage, and again when they are readied for shipment. POSCO's RFID system is comprised of UPM DogBone UHF tags, hand-held industrial PDAs, fixed RFID readers attached to cranes and placed at factory gates, enterprise resource planning and manufacturing execution systems, and a server. Because the RFID system integrates seamlessly with customers' own planning solutions via the internet, they can access real-time information on their products, using data to plan and fine-tune their own production operations.
By implementing the RFID-based logistics system, POSCO has automated the inspection, packaging, and shipping of its metal coil products. In addition to providing complete traceability of company products, the RFID system has decreased packaging and shipping errors, improving customer satisfaction and reducing costs by $1.4 million USD each month.
In recent years, RFID has been used to modernize and improve laundry management. RFID–enabled laundry applications are being used in hotels, casinos, government offices, hospitals, schools, professional sports, and other institutions that deal in employee uniforms, garments, and linens.
The benefits of implementing an RFID-enabled laundry system range from streamlining processes to eliminating inventory errors, decreasing manual labor, improving energy and water efficiency, and even reducing the spreading of disease. All of these benefits have a direct, positive impact the bottom line, which is often the case with enabling a process with RFID.
However, it’s not just the use of RFID in general that improves laundry management. It’s very specific capabilities that have been designed into in RFID tags and readers, and the manner in which they operate with one another that make this use of RFID truly innovative.
The RFID tags used in laundry management need to be able to withstand water immersion, extreme heat, pressure and chemicals. On the flip side, RFID readers need to be able to read tags simultaneously for clothing or other items that may be stacked or in piles. As the technology has evolved, UHF RFID solutions are beginning to replace other RF and proprietary technologies in this space (we are also seeing the same thing in waste management, tolling, access control, and other markets and applications). UHF has proved to be ideal for laundry management because, not only can it be used to identify and locate hundreds of items per second, but it also has the added benefit of reading items from greater distances.
For organizations that need to track their garment inventory in large batches, UHF technology allows them to eliminate the less efficient practice of single-piece barcode or proprietary tag scans. Further, they can eliminate or reduce the number of expensive, dedicated read stations which can lead to added time-saving and cost reduction benefits.
If a business doesn’t have a laundry facility on-site, the laundry is shipped elsewhere to be cleaned and sorted, which makes the management piece a little more challenging. If the laundry is done off-site, the implementation of RFID portals and use of tag directionality features can play a big role. It can be used to tell if the items are leaving or arriving for better inventory precision. Points of loss can be identified so that any necessary corrections can be made to prevent similar situations in the future.
The accurate and timely tracking of assets like laptops, mobile devices, and desktop PC equipment is a vital component of any profitable IT strategy. For many large global companies, tracking servers and server rack components distributed throughout data centers and across the world is equally important. Counting and tracking IT equipment has historically been done manually - which can be labor intensive, time consuming and prone to human error. These manual processes also provide a single snapshot in time and often need to be repeated frequently in order to provide a useful picture of inventory and its operating status.
RFID is quickly becoming the answer for many companies looking to automate IT asset tracking in data centers and enterprise office locations – delivering a new level of efficiency and addressing many of the challenges found with the manual processes mentioned above. And, though the thought of tracking hundreds of pieces of mobile equipment or thousands of server components might be too daunting of a task, deploying an RFID IT asset tracking system is not rocket science.
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| Photo credit: 1&1 |
NASA Takes One Giant Leap Forward
Famous for leading the United States’ space exploration efforts, NASA recently announced its installation of an RFID system to track thousands of pieces of equipment at its Langley Research Center. Covering a combined 30,000 square feet of data center, office and lab space, the RFID system deployed by NASA is used to track 1,500 servers and other computing devices, along with another 1,500 pieces equipment used by scientists both inside and outside of NASA labs.
To inventory its lab and data center equipment, NASA uses a handheld RFID reader and a combination of room-level tags, to provide information about what should be in the room, and item-level tags to identify specific devices. Discrepancy alerts are reported to the handheld user and are presumably addressed in real time. According to NASA, RFID has replaced both their use of paper and pen to track equipment serial numbers and the manual process used to check-out and return lab equipment. The result -- NASA has reduced the time required for their inventory counts from three weeks to a single day.
Shoot for the Moon
While significant time savings have been realized by NASA related to their datacenter inventory processes, can RFID be deployed in such a way to deliver a true real-time inventory view and further reduce the need for personnel to access each server rack to read tags attached to individual component?
For these installations, integrating a fixed RFID reader directly into the rack may provide a significant advantage. Tags designed for on-metal reading have come a long way, as have RFID antenna configurations and the performance of UHF RFID readers in this challenging environment. While NASA may not have requirements for this type of solution, those who operate large server farms do. With more high-bandwidth applications, like video, being used by consumers, datacenter growth is predicted to expand. With this expansion comes the need for innovative solutions – like in-rack RFID - to continue to advance operational efficiency.
Search Modes and Sessions can be a somewhat confusing concept at first. This post is designed to explain the differences and give examples of when you should use which settings. Any gen 2 reader works in this same fashion; however, for the purposes of this post, the screenshot below is from Impinj's MultiReader software connecting to the Speedway Revolution RFID reader.
Within Multireader, while in the Modes, RF, Power setting, you will see the option for setting "Search Mode" and "Session". What do these settings mean and how do they affect the performance of tag inventory?
Session Inventory Flags
Each EPC GEN 2 compliant tag has two states: 'A' and 'B'. The 'A' state is default when the tag powers up (or after 'B' state times out - more on that later).
Sessions
The EPC GEN 2 standard allows for up to four sessions; these sessions serve two purposes:
- Determines how often a tag will respond to a query from the reader
- Allows for multiple readers to conduct independent inventories
The RFID reader will select which session is to be used, each session's inventory flag can be independently set to 'A' or 'B' as shown below.
Persistence
Once the RFID reader inventories the tag, the flag state is changed from 'A' to 'B' - how long the tag stays in the 'B' state before reverting back to the 'A' state is called "persistence". It is important to realize that exact persistence times cannot be set by the user; they can only be approximated according to the Search Mode and Session - more on this later.
Next let's look at Search Modes and how they work with the Session setting to establish the persistence.
Search Modes
There are three search modes available on the Impinj Revolution reader: Dual Target, Single Target and Single Target with Suppression. "Target" in this case is referring to whether the reader will singulate (select) only tags that are in the 'A' state (Single Target) or if it will singulate tags in both 'A' and 'B' state (Dual Target).
In Dual Target, the reader reads all ‘A’ tags then moves all ‘A’ tags into ‘B’. Reader then reads all ‘B’ tags then moves all ‘B’ tags into ‘A’ and so on….
Additionally, in Dual Target, session has no influence as the reader will immediately 'push' tags back into 'A' state.
This search mode generates many reads and is good for small populations or static environments (i.e.smart shelf).
In Single Target, the reader reads all ‘A’ tags then moves all ‘A’ tags into ‘B’ and allows tags to stay quiet once they are inventoried. This mode is good for high population, dynamic environments (i.e. dock door portal).
Putting It All Together
So far we've discussed Sessions, Persistence and Search Modes; now let's put it all together to see the effect these settings have.
The image above illustrates what happens when a tag enters the read field according to the Search Mode and Session.
In Dual Target, the tag will be read continuously regardless of tag state 'A' or 'B'; the Session setting has no influence.
In Single Target with Session set to '1' the tag will be read and then moved to the 'B' state. After some period of time (TS1) it will revert back to the 'A' state and be read again. This TS1 value is defined in the EPC GEN 2 standard as being between 500ms and 5 seconds; again it cannot be expressly set, only approximated. The TS1 value will vary depending tag IC manufacturer and even specific tag IC model. For example, the Impinj Monza 3 S1 persistence is approximately 1 second whereas the Monza 4 is closer to 500ms. So, if we set the reader for Single Target, Session 1, we will see a Monza 3 tag being read about every second.
If the reader Search Mode is set to Single Target and the Session to either '2' or '3' then the tag will be read once then switch to 'B' state and remain quiet the entire time it is in the read field.
Once the tag leaves the read field, it will have a persistence (stay in the 'B' state) for a time period of TS2/3. This persistence time is only required by the EPC GEN 2 standard to be a minimum of 2 seconds with no maximum defined; it tends to be around 60 seconds but can be on the order of hundreds of seconds. Remember that during this time, the tag will not respond to a query from any reader using Single Target and the same Session.
Using Single Target with Suppression provides the advantage of Sessions 2 and 3 in that it will remain quiet while in the read field once inventoried thus allowing other tags which may be "quieter" (not reflecting as much power) to be read. It also provides the advantage of Session 1 in that it will revert almost immediately back to the 'A' state and be available for a reader query upon leaving the read field.
Examples
Let's look at some example scenarios:
Scenario 1: There are a number of tagged items being continuously inventoried on a RFID-enabled "smart shelf". Selecting Dual Target for the search mode will allow for the fastest update of tag status and be able to provide an update alert should a tagged item be put on, or taken off, the shelf.
Scenario 2: A fixed reader portal is performing an inventory on incoming items as they come off the delivery truck using Single Target, Session 2. Now, let's say you want to do a quick inventory sweep with a handheld reader (perhaps to encode the storage location). If the handheld reader uses the same session, it might miss some of the tags, or have a slow tag read rate, due to the fact that the tags were 'pushed' into the 'B' state by the fixed reader and have not yet flipped back to the 'A' state. Setting the handheld reader to a different Search Mode (i.e. Dual Target or Single Target w/ Suppression) or to Session 3, will allow the tagged items to be inventoried.
Another option would be to use Single Target with Suppression (assuming use of Impinj Monza tags) so that the large population of tags can be quickly inventoried with high probability of 100% count and still allow the tags to be re-inventoried almost immediately after leaving the portal read zone.
Scenario 3: Two readers want to simultaneously inventory a population of tags and then confirm they have the same count as a way of reducing missed tags. In this case, setting one reader to Single Target, Session 2 and the other to Single Target, Session 3 will allow this to happen.
POSCO, one of the world's largest steelmakers, has implemented a proprietary RFID-based logistics solution to track and trace multi-ton metal coil products from manufacturing through customer delivery. The automated solution is designed to improve the accuracy and efficiency of key operational processes. 
