These cards are valid for a specified amount of days or uses. Time and attendance to keep track of employees for payroll purposes. Status of a door can be monitored to see how long it has been open and whether or not it has been left ajar. Access control systems use keypads, card readers, proximity readers, data chip readers, barium ferrite readers, and barcode readers as ways to request a transaction. Card readers are designed for both indoor or outdoor use.
Keypads use push buttons similar to what a touch tone phone looks like.
Each user would have their own personal PAC or PIN and are usually 4-6 digits in length. Most systems have 48,000 different combinations or user codes. Some high security applications employ the use of a combination type readers that employ dual technologies. For example, the user would swipe their issued card and then enter their issued PIN on a keypad to request a transaction. This system helps to prevent the loss of a card allowing unauthorized use to occur.