The **ACTA-521-R** is a specific model of an **Intelligent Single-Door Access Control Board** (often associated with the ACTA series by manufacturers like *Advantage Controls* or similar security systems). It is designed to manage entry points by interfacing with readers, locks, and sensors. Below is a breakdown of its core electronic components and technical specifications. --- ### 1. Core Electronic Components The board consists of several functional groups that allow it to process data and control hardware: | Component Type | Description | Function | | :--- | :--- | :--- | | **Microcontroller** | High-speed integrated circuit | The "brain" that stores user permissions and processes input signals. | | **Relay (Form C)** | Electromechanical switch | Typically rated for 5A/12V-24V; used to trigger electric strikes or maglocks. | | **Wiegand Interface** | Communication Port | Interfaces with RFID, Proximity, or Biometric readers (Data 0/Data 1). | | **Non-Volatile Memory** | EEPROM/Flash | Retains the user database and event logs even if power is lost. | | **Voltage Regulator** | Power Management | Steps down input voltage (usually 12VDC) to logic levels (5V/3.3V). | | **TVS Diodes** | Transient Voltage Suppressors | Protects the board from power surges or "kickback" from magnetic locks. | --- ### 2. Connectivity and I/O Terminals The ACTA-521-R utilizes a series of screw terminals for field wiring. Understanding these is critical for installation: #### A. Input Terminals * **REX (Request-to-Exit):** Connects to a motion sensor or push-button to allow exit without a card. * **Door Status:** Connects to a magnetic door contact to monitor if the door is open, closed, or forced. * **Reader Ports:** Standard +12V, GND, D0, D1, and LED control for the external reader. #### B. Output Terminals * **Lock Output:** Provides the dry contact or powered output to engage/disengage the locking mechanism. * **Alarm/Aux Output:** Can be programmed to trigger a local siren if the door is held open too long. --- ### 3. Technical Specifications | Feature | Specification (Standard ACTA-521 Series) | | :--- | :--- | | **Input Power** | 12V DC to 15V DC | | **Current Consumption** | ~60mA (Idle) to 150mA (Active) | | **User Capacity** | Typically up to 1,000 - 5,000 users (model dependent) | | **Communication** | RS-485 or Wiegand (Inbound) | | **Operating Temp** | -10°C to +55°C | --- ### 4. Safety & Protection Features * **Optical Isolation:** Many versions use optoisolators on the communication lines to prevent electrical noise from the reader from crashing the main processor. * **Self-Resetting Fuses (PTC):** Protects the board from short circuits on the reader or lock power lines.