Access control systems

An access control system is a set of electronic devices that manage who is allowed to enter or exit a secured area — a building, a room, a gate, or any other physical boundary. Each user is identified by a credential (PIN code, RFID card, key fob, fingerprint, or a combination of these), and the system either grants or denies entry based on pre-configured permissions.

HDWR access control products are organised into four hardware families:

• Keypad encoders — wall-mounted PIN pads (with or without an integrated RFID reader) that authenticate users and signal the door release
• Proximity readers — RFID-based readers installed at doors; the user presents a card or fob rather than typing a code
• Electronic locks — self-contained electromechanical locks that replace or supplement a conventional lock cylinder
• Electric strikes — frame-mounted releases that work alongside a standard door latch or deadbolt; the bolt is held by or released by an electromagnetic or electromechanical mechanism

For information about standalone RFID readers used for identification and time-attendance (rather than door control), see RFID readers.

How the components fit together

A typical wired access control installation consists of:

1. Reader / keypad encoder — mounted on the unsecured (outside) face of the door; identifies the user
2. Exit button or secondary reader — mounted on the secured (inside) face; allows free exit or controlled exit
3. Electric strike or electronic lock — installed in the door frame or the door leaf; physically releases or engages the latch
4. 12 V DC power supply — provides stable power to the lock and the reader; a backup battery output protects against mains power loss
5. Optional: time-attendance recorder — the reader output is also forwarded to an HR system to log entry/exit timestamps

Wiring runs from the power supply to the lock, and from the reader to the lock's trigger input (or to a dedicated access control panel if the installation uses one).

Credential types

Credential	Technology	Notes
PIN code	Keypad	No card needed; simple to manage; susceptible to shoulder-surfing
Proximity card	125 kHz EM4100	Classic low-cost credential; no PIN required
Smart card	13.56 MHz MIFARE / ISO 14443	Higher security; some models support encrypted sectors
Key fob	125 kHz or 13.56 MHz	Same technology as cards, pocket-sized
Fingerprint	Biometric	Integrated on select encoder models
Multi-factor	PIN + card	Combines two credential types for higher-security zones

Wiegand interface

Many HDWR proximity readers output the credential identifier using the Wiegand protocol — the same open-collector two-wire (DATA0/DATA1) interface used by the vast majority of access control panels and controllers worldwide. The most common formats are Wiegand 26 (26 bits; 8-bit facility code + 16-bit card number) and Wiegand 34 (34 bits; supports larger card-number ranges). Match the format of the reader to the format expected by your controller or panel.

Power and fail-safe / fail-secure modes

Electric strikes and electromagnetic locks are powered devices. They operate in one of two modes:

• Fail-secure (fail-locked) — the door stays locked when power is lost; the lock requires an electrical impulse to open. Recommended for high-security areas.
• Fail-safe (fail-open) — the door releases when power is lost, allowing free egress in emergencies. Required by fire safety codes on evacuation routes in many jurisdictions.

Always verify local fire and safety regulations before choosing a fail mode.

Documentation in this section

• General information (this page) — system overview, component roles, wiring concepts
• Keypad encoders — PIN and PIN+RFID wall pads
• Proximity readers — RFID card and fob readers for doors
• Electronic locks — self-contained electromechanical lock units
• Electric strikes — frame-mounted electromagnetic / electromechanical releases

Access control systems FAQ

What is an access control system?

An access control system is a combination of electronic devices — readers, locks or strikes, and a power supply — that manages who may enter a secured area and when. A user presents a credential (PIN code, RFID card, key fob, fingerprint, or a combination), the reader verifies it, and if authorised it signals the locking hardware to release the door. The system can log every access event, allowing you to see who entered and at what time.

What types of access control systems are there?

The most common types are: (1) PIN-only keypads — the user types a code; (2) RFID proximity readers — the user presents a card or fob; (3) combined PIN + RFID readers — both methods work, either as alternatives or together for two-factor authentication; (4) biometric readers — fingerprint or face recognition; (5) standalone electronic locks — battery-powered, self-contained units that replace a conventional lock cylinder. HDWR products cover all of these, from simple PIN pads to dual-frequency RFID readers and fingerprint-capable encoders.

What do I need to build a complete access control setup?

A minimal wired system requires: a reader or keypad encoder (mounted outside the door), an electric strike or electronic lock (in the door frame or door), a 12 V DC power supply, and a short length of cable connecting them. For two-way controlled access add an exit reader or button on the inside. For time-attendance logging, connect the reader output to a compatible time recorder. An access control panel or controller is optional for simple single-door setups — many HDWR readers can trigger the lock directly.

What is the difference between an electric strike and an electronic lock?

An electric strike replaces the strike plate in the door frame and works with the existing door latch or deadbolt — the door handle and lock cylinder remain unchanged. An electronic lock replaces (or adds to) the entire locking mechanism on the door leaf and typically includes its own credential reader, making it a self-contained unit. Electric strikes are easier to retrofit; electronic locks offer tighter integration of the lock and reader in one device.

What is the difference between fail-safe and fail-secure?

Fail-safe (fail-open) means the door unlocks automatically if power is cut — useful on fire-escape routes where people must be able to exit freely in an emergency. Fail-secure (fail-locked) means the door stays locked when power is lost, which is preferred for high-security areas where unauthorised entry must be prevented even during a power outage. Check local fire and building regulations: evacuation routes almost always require fail-safe mode on the exit side.

What voltage do HDWR access control products run on?

Most HDWR electric strikes and proximity readers operate on 12 V DC. Some electric strikes also accept 24 V DC. Always check the specification sheet for the specific model — mixing voltages will damage the hardware. Use a dedicated access control power supply rather than a generic adapter, as dedicated supplies include short-circuit protection, an alarm output for tamper detection, and often a battery backup connector.