The **PM-R45-P** is a high-performance, U-shaped (slot) micro photoelectric sensor manufactured by Panasonic (formerly Sunx). It is widely used in industrial automation for sensing the presence of objects, limit detection, and counting. --- ### 1. Key Technical Specifications The "P" suffix in the model number denotes that this is a **PNP Output** type, which is common in European and North American industrial standards. | Feature | Specification | | :--- | :--- | | **Sensing Method** | Thru-beam (Slot type) | | **Sensing Distance** | 6 mm (fixed) | | **Supply Voltage** | 5 to 24 V DC ±10% | | **Output Type** | PNP Open-collector | | **Output Operation** | Dual: Light-ON / Dark-ON | | **Response Time** | 20 µs or less (under light received) | | **Current Consumption** | 15 mA or less | | **Protection Rating** | IP64 | --- ### 2. Internal Electronic Structure The PM-R45-P consists of several critical electronic components integrated into a miniature plastic housing: * **Infrared LED (Emitter):** Located on one side of the "U" slot. It emits a narrow beam of infrared light. * **Phototransistor (Receiver):** Located on the opposite side. It detects the beam from the emitter. * **Modulator/Demodulator Circuitry:** Ensures the sensor is resistant to ambient light interference. * **PNP Transistor Output:** When the sensor is triggered, it connects the Load to the positive rail (V+). --- ### 3. Wiring Configuration The device typically features 4 wires (or 4 pins). Below is the standard electronic pinout: | Wire Color | Function | Description | | :--- | :--- | :--- | | **Brown** | +V | Power Supply (5-24V DC) | | **Blue** | 0V | Ground / Common | | **Black** | Output 1 | PNP Output (Standard operation) | | **Pink** | L/D Control | Mode Selection (Connect to +V or Open for Light-ON/Dark-ON) | --- ### 4. Operational Logic Because the PM-R45-P features **Large Indicator** lights, it is easy to diagnose electronically: 1. **Light-ON:** The output is active when the light beam is NOT blocked. 2. **Dark-ON:** The output is active when an object is placed in the slot, breaking the beam. ### 5. Protection Circuitry The electronic design includes: * **Reverse Polarity Protection:** Prevents damage if the power wires are swapped. * **Short-circuit Protection:** Protects the internal PNP transistor if the load is shorted. ---