The **XTI-R** typically refers to the receiver unit of an active infrared (AIR) perimeter security system or a specific series of long-range infrared barriers. These devices are designed to detect intruders by monitoring a beam of invisible light. Below is an explanation of the core electronic components and their functions within an XTI-R unit. --- ### Core Electronic Components | Component | Function | | :--- | :--- | | **Photodiode / IR Receiver** | The "eye" of the unit. It converts incoming infrared light pulses into electrical signals. | | **Microprocessor (MCU)** | Processes signals to distinguish between a real human breach and environmental noise (like leaves or rain). | | **Relay / Alarm Output** | An electromechanical or solid-state switch that closes/opens the circuit to trigger an alarm panel. | | **Filtering Circuitry** | Removes ambient light interference (sunlight, car headlights) to prevent false alarms. | | **Alignment Indicator** | Usually a series of LEDs or a digital display showing voltage levels to assist in manual alignment. | --- ### Key Technical Systems ### 1. Optical System The XTI-R uses a specialized **spherical lens** or a parabolic mirror assembly. This focuses the incoming infrared beam onto the photodiode. High-quality optics are essential for "Long Range" (the "R" often denoting Receiver or Range) capabilities, allowing the device to work over distances of 100+ meters. ### 2. Signal Processing (Frequency Discrimination) The receiver does not just look for "light"; it looks for a specific **pulsed frequency**. * **Beam Modulation:** The transmitter sends light at a specific frequency (e.g., 38kHz). * **Discrimination:** The XTI-R electronics filter out any light that does not match this pulse pattern, ensuring that a flashlight or the sun cannot "trick" the sensor. ### 3. Environmental Disqualification (EDC) Advanced XTI-R units include an **EDC circuit**. If the signal strength drops slowly (due to fog or heavy snow) rather than abruptly (an intruder), the electronics can send a "maintenance" signal instead of a full alarm, or increase the gain to compensate for the weather. ### 4. Power Management * **Operating Voltage:** Typically 12V - 24V DC. * **Current Consumption:** Usually low (30mA - 70mA) to allow for long cable runs from the main security controller. --- ### Wiring Interface Standard XTI-R units provide a terminal block for the following connections: ```markdown 1. Power (+) [12/24V DC] 2. Power (-) [GND] 3. Alarm COM [Common] 4. Alarm N.C. [Normally Closed] 5. Tamper [Anti-sabotage switch] ```