### Access Control system

 

Closely manage access with the ASSA ABLOY (previously Besam) RD3A and RD4A1 access-controlled revolving doors.

• The access-controlled revolving doors ASSA ABLOY RD3A and RD4A1 are designed to handle the demands of restricted access in one direction. These doors are ideal for situations where the door needs to be open, but locked, or the door needs to be open without sacrificing climate control or increasing energy costs.
• The access-controlled revolving door ASSA ABLOY (previously Besam) RD4A2 creates an attractive yet highly secure entrance that controls access in two directions. An emergency break-away feature allows the door wings to swing open and create a clear evacuation path. By providing complete separation of the indoor and outdoor environments, this revolving door can help reduce noise as well heating and/or cooling costs.

Electronic The access-controlled revolving door ASSA ABLOY (previously Besam) RD4A2 creates an attractive yet highly secure entrance that controls access in two directions. An emergency break-away feature allows the door wings to swing open and create a clear evacuation path. By providing complete separation of the indoor and outdoor environments, this revolving door can help reduce noise as well heating and/or cooling costs.access control (EAC) uses computers to solve the limitations of mechanical locks and keys. A wide range of credentials can be used to replace mechanical keys. The electronic access control system grants access based on the credential presented. When access is granted, the door is unlocked for a predetermined time and the transaction is recorded. When access is refused, the door remains locked and the attempted access is recorded. The system will also monitor the door and alarm if the door is forced open or held open too long after being unlocked.[2]

When a credential is presented to a reader, the reader sends the credential's information, usually a number, to a control panel, a highly reliable processor. The control panel compares the credential's number to an access control list, grants or denies the presented request, and sends a transaction log to a database. When access is denied based on the access control list, the door remains locked. If there is a match between the credential and the access control list, the control panel operates a relay that in turn unlocks the door. The control panel also ignores a door open signal to prevent an alarm. Often the reader provides feedback, such as a flashing red LED for an access denied and a flashing green LED for an access granted.[4]

The above description illustrates a single factor transaction. Credentials can be passed around, thus subverting the access control list. For example, Alice has access rights to the server room, but Bob does not. Alice either gives Bob her credential, or Bob takes it; he now has access to the server room. To prevent this, two-factor authentication can be used. In a two factor transaction, the presented credential and a second factor are needed for access to be granted; another factor can be a PIN, a second credential, operator intervention, or a biometric