The **PM-R25-R** is a specialized U-shaped (slot) photoelectric micro-sensor manufactured by Panasonic (formerly Sunx). It is designed for high-reliability sensing in automated machinery. --- ### 1. Key Technical Specifications The PM-R25-R is part of the PM-25 series, known for its compact size and high resistance to vibration. | Feature | Specification | |:---|:---| | **Sensing Method** | Thru-beam (U-shaped) | | **Sensing Distance** | 6 mm (fixed) | | **Output Type** | NPN Open-collector (Dual output: Light-ON / Dark-ON) | | **Supply Voltage** | 5 to 24 V DC ±10% | | **Current Consumption** | 15 mA or less | | **Response Time** | 20 µs or less (under specific conditions) | | **Cable Type** | Flexible (R-type) Robotic Cable | --- ### 2. Electronic Components & Internal Logic The internal circuitry consists of three primary stages that handle signal emission, detection, and output switching. #### A. The Emitter (Infrared LED) The device contains an **Infrared LED** located on one side of the "U" slot. It continuously emits light across the 6mm gap. * **Wavelength:** Peak emission is typically in the infrared spectrum (~880nm). #### B. The Receiver (Phototransistor) On the opposite side of the slot sits a **Phototransistor**. * When an object enters the slot, it blocks the light beam. * The change in light intensity is converted into an electrical signal. #### C. The Output Stage (NPN Open-Collector) The "R" in the model name indicates the inclusion of a **Flexible/Robotic cable**, but the electronic output remains NPN. * **Dual Output:** It provides two separate output wires. One triggers when light is received (Light-ON), and the other triggers when the beam is broken (Dark-ON). * **Open-Collector:** This means the sensor acts as a switch to the ground (0V). You typically need a pull-up resistor if the connected PLC or controller doesn't have one internally. --- ### 3. Wiring Diagram Representation The PM-R25-R usually features a 4-wire configuration: ```mermaid graph TD VCC[Brown: +V 5-24V] OUT1[Black: Output 1 Light-ON] OUT2[White: Output 2 Dark-ON] GND[Blue: 0V] ``` --- ### 4. Distinctive Features * **Robotic Cable:** The "R" suffix signifies a high-flex cable designed to withstand repeated bending, making it ideal for moving parts or robotic arms. * **Large Indicator:** Includes a large, bright red LED indicator that lights up when the output is active, visible from multiple angles. * **Protection Circuitry:** Built-in reverse polarity protection and output short-circuit protection to prevent damage during installation errors. ---