Access Control is simply allowing the right people into an area at the right time, or "Saying who can go where when".

It provides management of access to doors, elevators, alarm areas and more. It is able to programme user credentials, access levels, timezones, public holidays and more. It can be programmed and monitored via an easy to use Windows based software which stores user information & provides powerful audit trail reporting facilites.

An example: The public is allowed in the front door during office hours. The door will automatically unlock at 9am and lock again at 5pm. Anyone outside the building can get inside during these hours.
On the same door, it is necessary to allow people to enter outside these times. They will be issued with a credential (eg a card, key or other identification means). They will then be assigned times in which they can enter. Some people may only have extended hours (eg 6am to 11pm Monday to Friday), while others may have 24 hour access. It is possible to restrict access through doors, driveways and lifts.