Devices function is user identification and verification his right to pass through doors by steering electromagnetic lock?s state. Standard standalone circuit is composed of card readers or keypad sets and control unit.

Even basic devices are equipped with controllers with user buffer and have options connected with i.e. doors opening time. More advanced devices have inputs that allow them to monitor doors state, event buffer, real time clock. Device programming can be done with help of built-in keypads or with help of Master card. Some devices have additional RS232/RS485 joint for configuration via PC.

User identification is being made with few digit PIN code (keypads) or proximity cards (readers). Some devices provide higher level of security and require both code and card.