Special Edition | April 13, 2005
This week, I had my first opportunity to work with UHF Gen 2 tags and readers while at the RFID Journal Live conference. Everything out there is an engineering prototype, which means they are pre-alpha versions. Of the units I could get my hands-on, I decided to do some experimenting. Here's what happened.Bright and early as we set up, ThingMagic came to our booth and upgraded the firmware of our Mercury 4 reader. The process only took about 5 minutes. We were given a few sample Gen 2 tags that have an Impinj chip and an Avery-Dennision tri-flex antenna. We held the tag in front of the antenna and viola, we read the EPC number. Proudly carrying a new Gen 2 tag, I boldly strode to other vendor's booths and asked if I could try my tag with their reader.
My first stop, Alien Technology. Alien has upgraded the firmware of their ALR-9780 reader so it works with Gen 2. I waved my tag in front the antenna, and it didn't read. Of course, I was disappointed, so I inquired about Alien's tags. For Gen 2 tags, Alien has something called an emulator tag. This is a circuit board about 3 inches long by 1 inches wide with a built in antenna and a battery, which is required to power the circuit board. (No, the battery does not make it an active tag.) Production versions will not have a battery. The emulator tags work with the Alien reader so I took them to my ThingMagic reader and they instantly read. This added to my confusion.
I continued in my madness with Ron Gilbert from Integral RFID and Rychee Parmann from Precisa in tow. We proceeded to visit other vendors that had Gen 2 readers, including AWID, Impinj, and SAMSys; and we tested Gen 2 tags from Avery-Dennison, Precisia, and Alien Technology. The results were mixed. No reader could read every tag, but every tag worked with at least two different readers.
What would cause such results? The Gen 2 specification is extremely complex. The requirement for a Gen 2 product is strict verification to 450 requirements. Depending on your perspective, that may not seem like a lot, but when you start to develop test cases to ensure a product meets all the requirements, you quickly realize you've got your hands full. One manufacturer shared with me that their verification process has 363 test suites and the average test suite has 64,000 tests. Their QA department will be working overtime during the next few months.
Obviously, there's still a lot of work to be done. Needless to say, EPCglobal conformance is much more comprehensive than me running from booth to booth waving tags in front of readers. Although I did provide some laughs for on-lookers.
| Tag | Alien Technology ALR-9780 | AWID MPR-2010 BR/BN | Impinj Reader Ref. Device | Samsys MP-9320 | ThingMagic Mercury 4 |
| Alien Technology emulator | Y | N | N | N | Y |
| Impinj, Precisia Propeller antenna | N | Y | Y | Y | N |
| Impinj, Avery Tri-flex antenna | N | Y | Y | Y | Y |
