What we use to control access to computer areas is magnetic
swipe cards. These systems are a bit pricey but they allow you to
track all entry (on a computer), permit a unique card for each
person, and access can be very simply limited (timewise,
termination-wise). Another plus is they also record attempts at
access that didn’t succeed. Best place to ask about these is at
an alarm shop. Once you have the base system installed the per
door cost drops.
A cheaper solution is to alarm the door and have a keypad to
turn off the alarm to allow entry then auto-arm itself again.
Most alarm places should be able to set something like that up
I can ask for details if you want (the company that supplies
them is a client - also is in the same building as our office).
Cameron Speedie (Daytime Systems Engineer - Nighttime Lapidary)
Island Gem and Rock