The **M2UDS-FWA-R2** is a specialized electronic component, typically categorized as a **Magnetic Proximity Sensor** or a **Door/Window Contact Sensor**, often used in fire alarm systems or security monitoring. Below is a breakdown of its electronic characteristics and functional parts. --- ### 1. Technical Specifications The device operates as a passive electronic component, meaning it does not require a constant power supply to function, but rather acts as a switch within a loop. | Parameter | Description | | :--- | :--- | | **Sensor Type** | Magnetic Reed Switch | | **Contact Form** | Normally Open (NO) / Form A | | **Material** | ABS Plastic Housing (Fire Retardant) | | **Switching Voltage** | Usually up to 100V DC/AC | | **Switching Current** | 0.5A (Typical) | | **Gap Distance** | 15mm - 25mm (Detection Range) | --- ### 2. Core Electronic Parts The internal architecture of the M2UDS-FWA-R2 consists of two primary assemblies: #### A. The Reed Switch (Sensor Unit) This is the "active" part of the circuit. - It contains two thin metal reeds (usually nickel-iron) encapsulated in a glass tube. - When a magnetic field is applied, the reeds become polarized and pull together, closing the circuit. #### B. The Permanent Magnet (Actuator) - A high-coercivity magnet (often Alnico or Ferrite) encased in a matching housing. - It is mounted on the moving part (the door), while the reed switch is mounted on the frame. #### C. Loop Wiring (Terminals) - **Terminal Block/Pigtails:** Used to connect the sensor to a Fire Alarm Control Panel (FACP) or a Security Controller. - **Internal Resistor (Optional):** Some versions include an internal EOL (End of Line) resistor to allow the panel to monitor for wire-tampering or short circuits. --- ### 3. Functional Operation The electronics follow a simple logic state: 1. **Proximity State:** When the magnet is close to the sensor (door closed), the magnetic field closes the reed switch, allowing current to flow through the monitoring loop. 2. **Alarm State:** When the magnet moves away (door opened), the magnetic field dissipates, the reeds spring apart, and the circuit is broken (Open Circuit), triggering an alert on the control panel. --- ### 4. Circuit Diagram Representation In a standard security or fire loop, the wiring usually looks like this: ```mermaid graph LR A[Control Panel +] --- B[M2UDS Reed Switch] B --- C[End of Line Resistor] C --- D[Control Panel -] ``` ---