The access control readers are used by a cardholder to access an area through. usually a door, but can also be used to open barriers. turnstiles. elevators and sliding gates
Readers, when used on a door. are mounted at a height of between 0.9 and 1 meters from the floor. This height is to comply with Equality Act requirements. The location of the reader will depend on the building and door layout however, it must not be located at a distance from the door that makes it difficult for the user to open the door before the door locks again after the programmed open time has expired

it is not uncommon fora reader to be installed on both sides of a door thereby ensuring the cardholder has the correct access to enter and leave the area
Readers are available in many sizes which are also used to determine how far away from the reader the credential is able to be read
With the larger size readers a bigger antenna can be installed internally and therefore increase the size of the reading area of the reader
In addition to the antenna that supplied power to the card to allow it to send its contained number back to the door controller. the reader contains an LED that signals if the door has been opened. a buzer (although not typically used). and in the case of some specialty readers. An R S 232 output that allows connection direct to a PC
A reader is connected to the door controller via a screened 6 core cable. of which, 5 cores are typically used
The cable carries the power on 2 cores, the LED control on another and the final 2 cores are used to carry the credential access control number once it has been read
The credential number is carried across these 2 cores as either Wiegand or Clock and Data; discussed later on
When using any reader. the manufacturers recommended cable type and connections should be confirmed from the installation guide
Readers are available that contain inbuilt keypads which allow the access control system to add an additional level of security to the door or access portal
Within the access control software. Schedules can be set that allow the reader to function as keypad only, card only, card and keypad. With the schedules, a main entrance door can be set to operate on card only during normal working hours and then card and pin after hours
‘When a button is pressed the number is transmitted along the 2 cores, which the credential number also uses, and is decoded by the door controller so it knows what button has been pressed