Access Control Systems

What Is an Access Control System?

Access control systems are security solutions that define who can pass through which door of a building on which days and at what times, and record every passage. In Turkish they are known as "geçiş kontrol", while the international term is access control. Unlike keyed locks, a lost card is cancelled in the software with a single click and no lock needs to be replaced; an employee can be allowed to enter only their own department and only at certain hours.

How Do Access Control Systems Work?

An access control system consists of four basic components:

• Identification device (reader): Reads a card, PIN, fingerprint, face or QR code.
• Access control panel: Compares the information from the reader with the permission list and decides whether to unlock. On some devices, the panel and reader are in a single housing.
• Lock or passage hardware: Magnetic lock, electric strike, turnstile or barrier.
• Access control software: The hub where users, permissions, time schedules and reports are managed.

When a user verifies their identity, the panel unlocks the door for a set period; a door sensor monitors whether the door has been left open or forced. For exiting from the inside, an exit button or a second reader is used.

Types of Access Control Systems

Card access control systems

The most common and easy-to-use systems, working with proximity or encrypted cards. Cards can be combined with the staff ID card. See card access control system.

PIN-based systems

Operate with a keypad; there is no additional card cost, but there is a risk of the PIN being shared. They are usually chosen as a second factor alongside a card.

Biometric systems

Fingerprint or face recognition requires the person to be physically present. They stand out in sensitive areas such as server rooms, archives and laboratories. See face recognition systems. Under KVKK, biometric data is considered special category personal data. The Turkish Personal Data Protection Authority (KVKK) principle decision No. 2026/921 of 29.04.2026 does not find processing this data for working-time tracking proportionate; although the decision does not directly regulate access control for security purposes, using biometric devices in high-security areas requires a separate legal assessment. We recommend consulting a legal advisor before installation.

QR code and mobile access

Visitors are sent a temporary QR code, allowing controlled entry without issuing a card; this is becoming common in office towers and corporate buildings.

Comparison of Types

What Do You Gain with an Access Control System?

Key management is largely eliminated: when an employee leaves and their card is cancelled, there is no need to change locks. Since separate permissions and time schedules can be defined for each door, for example, only the relevant team can enter the accounting archive during working hours. Because all passages are recorded, after an incident you can look back at who passed through which door and when. An alarm can be generated if a door is left open or forced. The same infrastructure can also be used for time attendance and visitor management, bringing several needs together in a single system.

Visitor Management

In office towers, factories and corporate buildings, visitors are the least controlled user group. With a visitor module added to the access control software, a guest can be issued a card or QR code valid only for specific doors and for a limited time. When the period expires, the permission ends automatically and the visitor's movements in the building remain on record.

Choosing a Lock

In the field, the end result of access control is the lock. Magnetic locks are common on glass and aluminum doors, and electric strikes on wooden and steel doors. For doors on fire and emergency exit routes, a lock type that opens the door when power is cut and integration with the fire alarm should be planned. For lock options, see our lock systems page.

How to Choose an Access Control System

• How many doors and how many users will be managed?
• Are different permission levels needed between doors?
• Will the system also be used for time attendance (PDKS)? If so, card (RFID/NFC) or PIN readers should be preferred.
• What are the door types and emergency exit requirements?
• Is visitor management needed?
• Is integration with cameras, fire alarms or lift systems required?

What Determines the Price?

• Number of doors and readers, reader type
• Whether a central panel or a standalone single-door device is used
• Lock type and mounting brackets suited to the door
• Software scope and number of users
• Cabling distance and network infrastructure
• Additional components such as cards and a visitor module

Installation Process

During the site survey, each door is examined and the lock type and cable routes are determined. Cabling is laid, readers, panels and locks are mounted, and exit buttons and door sensors are connected. Users, permission groups and time schedules are defined in the software. After emergency scenarios are tested, administrators receive training. If you also want to use access data for time attendance, records from card or PIN readers can be connected to the time attendance systems infrastructure with our in-house software.

Maintenance

The holding force of locks, the adjustment of door closers, the operation of readers and the currency of permission lists in the software should be checked regularly. Revoking the permissions of departing staff on time is the most important security step in the system. Regular backups of the software database and keeping device firmware up to date should not be neglected either.

Sensör Yazılım provides free site surveys in Istanbul, works with devices from various brands and ships to all 81 provinces of Turkey. Get a quote for your building.