Traditionally, access control is the selective restriction of access to a particular location or space within a location. Access control is typically implemented through locks and valid login credentials. In general, physical access control is a matter of who, where, and when: who is allowed to enter or exit, where they are allowed to exit or enter, and when they are allowed to enter or exit.
A simple example of physical access control is the use of turnstiles into a stadium. While the turnstile is not built to keep people from entering, it does control the flow and force people to enter slowly and individually. Similarly, the historical form of access control that restricts access unless the person has an authorized entry method is the lock and key method. Typically, only persons with a valid key can unlock the door and enter. However, as we know, people have found ways to bypass such a system and break in, which is why more sophisticated access control methods have been developed and implemented.
Today a wide variety of sophisticated access control technologies are available depending on your need. Electronic access control systems can use a wide range of credential options instead of mechanical keys. Once access is granted, the door is unlocked for a predetermined period of time and the transaction is recorded. When access is denied, the door remains locked and the attempted access is also recorded. The system can also monitor the door and sound an alarm if the door is forced open or held open beyond the predetermined period of time after access was granted.
An access control system has several components, including an access control point, a lock, a reader, a door switch, a request-to-exit control, and an alarm. The following is a list of types of readers that could be used.
Types of Readers:
- Basic (non-intelligent) readers – simply reads the card number, PIN, or in the case of bio-metric identification, the user’s unique ID, and forwards it to the control panel.
- Semi-intelligent readers – controls door hardware like locks, contacts, and exit buttons, but does not make any access decisions.
- Intelligent readers – controls door hardware like locks, contacts, and exit buttons, and independently makes access decisions.
Access control systems make decisions about granting or denying access by comparing the credential to an access control list. This look-up is done through a host or server, an access control panel, or a reader. The predominant arrangement is usually a hub and spoke setup with a control panel, which does the look-up and controls access as the hub and the readers as the spokes. Controllers are usually IP enabled and connect using standard networks. Below are some examples of possible access control setups United Safety & Alarms can implement for you.
Several different sensor types can be used within the burglar alarm system, including:
- Passive infrared detectors
- Ultrasonic detectors
- Microwave detectors
- Passive magnetic field detection
- Vibration or inertia sensors
- Photo-electric beams
- Glass break detectors
- Smoke, heat, and carbon monoxide detectors
- Taut wire fence systems
- Serial controllers – Controllers are connected to a host PC via a serial RS-485 communication line
- Serial main and sub-controllers – All door hardware is connected to sub-controllers, which usually do not make access decisions but instead forward all requests to the main controller
- Serial main controllers & intelligent readers – Door hardware is connected directly to intelligent or semi-intelligent readers
- Serial controllers with terminal servers – Access control with servers not connected to a network
- Network-enabled main controllers. – Access control with servers not connected to a network
- IP Controllers – Controllers connected to a host PC via Ethernet LAN or WAN
- IP Readers – Readers connected to a host PC via Ethernet LAN or WAN