Dec 1, 2004 12:00 PM, By Steve Filippini
From the early days of numeric keypads to today's integrated card systems that provide access for more than 50,000 users, security systems have come a long way.
The first alarm company I ever worked for introduced me to the concept of restricted area access. It was a small company with a lobby about 10'×15' and a small desk reserved for the receptionist. The door leading into the business from the lobby remained locked, and on the wall next to it was a small, silver-plated keypad about 5ft. off the ground.
In the security magazines I read about the latest access systems, I can't help but marvel at how far we've come. Thumbprint readers, retina scanners, voice pattern readers, and hand scanners (like the one above from Schlage)—each is designed to keep unauthorized people out of a secure area.
The keypad had six numbered buttons and two LEDs — one red, one green. When you pressed the correct four-button sequence, the red LED changed to green, a loud buzzing erupted from the doorjamb, and if you pulled on the knob the door would open. Magic. If you were a trusted guest, the receptionist pressed a button under her desk, and the door buzzed open.
I was fascinated by the Corby keypad. Different colored wires with diodes in the tips and a relay module that could handle the AC current from a standard door strike was the leading edge of technology. The colored wires, depending on the holes they plugged into, determined the access code. If you forgot the code, no problem, you could simply remove the two screws holding the faceplate to the wall and read off the sequence (or short the open wires powering the door strike and waltz on in).
At the time, the only other access option I could offer customers was the push-button combination locks. These were good for doors that didn't have a power source nearby or for customers who only needed one or two restricted doors and couldn't justify the cost of an electronic system. I used to trust locks of that design for years, until I recently read on the Internet how to decipher the coded sequence using some common sense and patience.
My experience with secured area access remained at that level for many years until I was introduced to a Schlage card access system. The electronic key carried by the customer was about the size of a credit card and twice as thick. Imbedded in the card was a circuit board with a distinct electronic pattern. When presented to an electronic reader, it deciphered the card's pattern and granted access.
The Schlage system used a proximity-based receiver, meaning the card didn't need to touch the reader; it could stay in your wallet when presented. The reader was usually outside next to the access door used by employees and maintenance crews.
Other access systems I installed and supported used a credit card-based reader. A magnetic strip with specific information recorded was glued on one side of the card and a company logo or employee photo was on the other side. This access key could be carried on a chain or hung around the neck using a lanyard. The card was swiped through a reader (think of the ATM readers at your local grocery store), and the electronics did the rest. Aside from the bulky hardware mounted on the wall next to the door, the customers were content. Then came the era of corporate interior decorators. Practical was no longer the priority; now it had to look good too.
Today's card readers don't have to look like rectangular chunks of iron with a slot since magnetic strip readers are not as popular as they once were. Too many things can happen to magnetic strips: tears, worn out spots, cards disabled from encounters with magnets. Such things can ruin your whole day. And quite possibly leave you outside in the rain. Also, magnetic strip readers are often located outside and subjected to the elements. Rain, fog, and snow can coat the metal contact readers and oxidize them, reducing their ability to read strips. This is one of the reasons why proximity card access systems are now the standard.
Readers resembling black baseball plates have been replaced with 3in. to 4in. square slim-line models. Even General Electric has a new line of card access readers that look just like plug-in Glade air fresheners. I mentioned that to GE representatives the other day and received a daggered stare in response. Access cards no longer have to be credit card-sized either. Now they can be tokens no bigger than your thumb and hang off your keychain. My access token is on a retractable leash that attaches to my belt. It all depends on how convenient you need it to be. Let's face it, as long as it unlocks the door, where you stow it is a secondary concern.
Now's a good time to take a quick moment to discuss devices that keep doors closed to unwanted visitors: door strikes and mag-locks. Door strikes live in jambs and allow access without turning a doorknob. Door strikes are designed as either “fail open” or “fail close.” All this means is that in the event of a power failure, the door will either unlock or remain locked. Fire marshals frown on fail close models and will require an automatic override to unlock the doors if the fire alarm system activates.
Mag-locks are usually located at the top of the doorframe and hold the door closed via a powerful magnet, which keeps a metal plate on the door in place. Back-up power is a good thing to have available, unless you don't mind waiting outside (or inside) until power is restored. Mag-locks are extremely powerful and won't fail to keep a door secure when they are installed correctly. Mag-locks come in sizes based on how much force they can withstand before they are pried open.
As with most everything else, the introduction of computers for security systems revolutionized card access requirements. Instead of a combination residing in a self-contained keypad, today you have a dumb keypad attached to a microprocessor with options. Entering a correct combination doesn't just open doors anymore. Now you can initialize a sequence that bypasses certain door annunciators, arms/disarms security systems, turns lights off and on, and unlocks doors as needed.
Bosch (Radionics) uses an integrated card access system for small-end systems. Four doors here, three doors there, all you need is an optional module for each opening, some wire, and the correct door hardware. Northern Access provides card access for high-end systems that can cover thousands of programmable users. GE has a system that can provide card access for more than 50,000 users. I believe that number of users will soon decrease as system resources are allocated to other features/functions deemed necessary by the company's marketing department.
You have to ask yourself, why do high-end system providers advertise their ability to assign up to 50,000 access cards? At some point you have to concede that it's easier to leave the doors unlocked and post a guard. Maybe this would be practical for government installations where a card holder might have limited access, but at some point you have to draw the line.
Regardless of the bells, whistles, and fancy packaging, card access systems are based on relays and timers that follow directions from a smart sequencer. They follow if/then protocols. If the input is verified, then the output is activated. It's that simple. Card access systems are typically used to restrict access to pharmacies, cash rooms and vaults, and high-valued stockrooms. These systems may have an audible device nearby to alert a manager of its use.
I have one national account where an access card is required to enter and leave a cash room. I don't understand the reason why, unless they plan on leaving someone in the room until an authorized cardholder lets them out. Sometimes it's safer to just do what you're told and not ask questions.
I read in the security magazines about the latest access systems out there and can't help but marvel at how far we've come. Thumbprint readers, retinal-scan readers, voice pattern readers (God forbid you catch a cold and lose your voice) — each of these systems is designed to keep unauthorized people outside a protected area.
And who knows what the future holds for these access systems? I have a buddy who truly believes he can design a biorhythm sensing system that only allows access when you are in the correct frame of mind. I plan on investing in this venture. If he pulls it off, I can retire and hire someone to write these columns for me.
Steve Filippiniis a senior technician with more than 20 years of experience in the security and installation industry. He can be reached firstname.lastname@example.org.