Card Access Control Systems
When it comes to access control, there are a lot of terms being thrown about – especially when it comes to card access. Swipe cards, prox cards, RFID cards, smart cards; it seems like an endless list of cards all doing the same thing. So what’s the difference between all these different types of card access control, and which kind is right for you? Keep reading to find out.
Proximity or Prox Cards
Prox cards can be made of several different materials, but they all work in the same way; by being held in close proximity to the card reader, without needing to make physical contact with the reader. This sets them apart from swipe cards or other contact-style cards, which need to actually make physical contact with the reader.
Prox Cards can be Active or Passive, both running off 125 kHz radio frequencies. Passive Cards are powered by radio frequency (RF) signals from the reader that read the encoded number embedded on the card. These are the much more common form of prox card in use for access control.
Active Prox Cards, on the other hand, are powered by internal lithium batteries, sending out their own 125khz frequencies to contact the card reader. They generally have greater range (up to 5 or 6 feet), but the battery must eventually be replaced. When it comes to access control, however, they are not used nearly as often.
Prox cards almost always use some form of the Wiegand protocol to communicate with the card reader. Basic Prox Cards are usually thin, the same size as a credit card, and made from PVC with a wireless antenna embedded in the plastic. Clamshell prox cards use two different layers of PVC glued together, with the antenna between them, while composite prox cards use a blend of PVC and polyester.
Swipe cards, also sometimes called magnetic stripe cards, function using none other than a magnetic stripe, almost exactly like those found on credit cards. At the most technical of levels, swipe cards work first by modifying the magnetism of the particles contained in the magnetic stripe on the card, which then picked up and read by the magnetic reading head found in the card reader at the access point.
All you need to know, however, is that a swipe card works by being swiped through the card reader at the door, and the user’s access code and credentials are immediately read. Swipe cards are one of the oldest forms of card access out there (if not the oldest) and are generally reliable – though the magnetic stripes do tend to wear out over time. They are widely being replaced with tougher, more secure cards as time goes on.
Smart Cards are the latest in access control card technology and, as the name implies, the most advanced. Contactless smart cards are like proximity cards, but further build and improve on the original technology. Instead of running off 125 kHz frequencies as prox cards usually do, smart cards run much faster, usually transmitting at 13.56 mHz – which is far faster, more powerful and reliable. They are also capable of writing data, in addition to just reading it, which allows them to store much more information and makes them useful in a whole host of different applications, in addition to standard access control uses.
Like regular passive proximity cards, smart cards do not have an internal power source, instead using inductors to conduct an RF signal from the antenna embedded in the card reader when placed within proximity. Data can travel at much faster speeds – anywhere from 106 to 848 kbits/second – which makes them excellent when speed is crucial (hence why they are often used on public transport systems). Furthermore, smart cards can store much more data than traditional 125 kHz proximity cards, allowing for a whole host of credential options.
Combined Smart/Prox Cards
Furthermore, smart cards are capable of being combined with other card technologies, such as prox cards or magnetic stripes, allowing for a whole range of customizable access credentials, information storage and enhanced security within a card access system.
What About RFID Cards?
Another term you will see frequently being discussed, as it relates to card access control, is RFID Card. While RFID cards might sound like another technology of their own, RFID merely refers to the technology that prox cards already use: Radio Frequency. RFID stands for Radio Frequency Identification, and is used when necessary for identifying an object, whether that’s a package in transit or a car in production. RFID Card is simply another way of referring to a proximity card, in this case by the actual technology.