Penn switches to prox ID cards

Penn state university is yet another large institution replacing magnetic stripe id cards with proximity tags. The trend has been set a while ago but it doesn’t mean everyone switched overnight. Progress is never free and this case is no exception.

Magstripe cards, developed in early 1970s by IBM have served many industries for years and they will stick around for some more time. The fact that new technology, far better in many ways is out there doesn’t necessary mean there is no more room for the old school technology. Naturally many technology enthusiasts pronounced this solution dead more than once yet just like personal computer it was more to make headlines than accurate diagnosis.

Magnetic strip as a data carrier has 2 undeniable advantages: price and simplicity. Both features allow for quick and very broad application which made it the most popular technology in retail credit and debit card sales. Such popularity means large amount of inertia to combat when looking to replace. To give the standard even more boost it was split into two flavors. High coercivity striped cards would be applied where high read (swipe) volume was expected, carrier in the form of nearly solid black stripe is very wear resistant but much stronger magnetic field would have to be employed in order to change the data stored. Such tags would often by programmed once for the lifetime. Credit, debit and mass transit access cards are the most popular example of Hi-Co cards. Low coercivity cards (Lo-Co for short) on the other hand require less energy to program and reprogram the data but at the same time cannot endure the same number of swipes. Such cards with light brown stripe find its use as hotels electric door keys and theme park access tags.

Proximity cards are anything but simple but at the same time it’s not a man landing on the moon complication level. The standard was developed in early 1970s allegedly in response to railroad systems need to track the freight cars. Since it’s hard to develop a mechanism for a cargo train car to swipe a card against the reader a contactless solution would have to be found. Two different technologies have emerged to address such scenarios. Scannable barcode was one of them and it secured a supremacy position in retail industry. Second one was the radio frequency proximity tag which outshined barcodes in access control technologies and tracing devices.

Barcode biggest advantage lies in its versatility, the image could be placed on virtually any printable material. Therefore the standard has no competition when cost is a factor however the solution is flawed with a limitation that could matter in many situations. If you have ever tried a self checkout at your local grocery or home improvement store there is a good chance you struggled to scan a product barcode. This is due to the fact that laser scanner has limited angle of the reading scope; it also lacks tolerance for any barcode contamination or wrinkles. All these inhibitions need to be taken into careful consideration wherever automated reading is a baseline requirement. prox coil

Proximity card or tag could guarantee positive communication regardless of the angle as long as the distance conditions are met and no interference occurs. This advantage comes at a higher ID badges price due to more expensive component materials. Heart and brain of each proximity id badge is a coil usually made of copper wire which plays two important roles. One is antenna transmitting radio waves on one of 3 standard frequencies, 125 kHz, 400 kHz or 13.56 MHz. Second function is to generate power; when a tag reaches the area of a reader device emitting electromagnetic field it generates electric power needed for reading and passing the data over radio waves.

Making a proximity device is fairly simple, squeezing it into a slim ID badge so it could double as an access card is whole another story. Early adoptions of prox ID tags were closer in thickness to a wallet than a credit card, even couple of years ago standard proximity card would be 100mil thick (ordinary id card is 30 mil) moreover it wasn’t printable. Workaround was to print a slim 10 mil sticker and attach it to the tag. This was bothersome enough for the adopters and manufactures managed to make a 30 mil thick, printable radio frequency ID card. Same one as Penn state decided to use.