The **PM-R24P** is a small, U-shaped photoelectric sensor manufactured by Panasonic (formerly Sunx). It is widely used in automation for position sensing, limit detection, and counting. --- ### 1. Key Technical Specifications The "P" in the model name indicates that this specific version uses **PNP Output** logic, which is common in European and American industrial systems. | Feature | Specification | | :--- | :--- | | **Sensing Method** | Thru-beam (U-shaped) | | **Sensing Distance** | 5 mm (fixed slot width) | | **Supply Voltage** | 5 to 24 V DC ±10% | | **Output Type** | PNP Open-collector transistor | | **Output Operation** | Dual output: Light-ON / Dark-ON | | **Current Consumption** | 15 mA or less | | **Response Time** | 20 µs or less (under specific conditions) | | **Protection Rating** | IP64 (Dust-tight and splash-resistant) | --- ### 2. Internal Electronic Components The PM-R24P functions by aligning an emitter and a receiver across a 5mm gap. * **Infrared LED (Emitter):** Located on one side of the "U" arm. It emits a beam of infrared light that is invisible to the human eye. * **Photo-transistor (Receiver):** Located on the opposite arm. It detects the presence or absence of the IR beam. * **Schmitt Trigger Circuit:** An internal circuit that converts the analog signal from the photo-transistor into a clean, digital "square wave" to prevent flickering or false triggering near the threshold. * **PNP Output Transistor:** When triggered, it connects the output load to the positive supply voltage (V+). --- ### 3. Wiring Diagram and Pinout The sensor typically features 4 wires (or 4 pins). Because it has **dual outputs**, you can choose how the sensor behaves when the beam is broken. | Wire Color | Function | Description | | :--- | :--- | :--- | | **Brown** | +V | Positive power supply (5-24V DC) | | **Blue** | 0V | Ground / Common | | **Black** | Output 1 | **Light-ON**: Conducts when the beam is unobstructed | | **White** | Output 2 | **Dark-ON**: Conducts when an object blocks the beam | --- ### 4. Connection Example (Code Block) Since this is a **PNP** sensor, the load (PLC input or Relay) must be connected between the **Output wire** and the **Negative (0V) line**. ```text [ Power Supply + ] ---- (Brown Wire) | [ PLC Input ] --------- (Black or White Wire) | [ Power Supply - ] ---- (Blue Wire) AND (Other side of PLC Load) ``` ### 5. Mechanical Advantages * **Large Indicator:** Features a large red LED operation indicator that can be seen from multiple directions. * **M3 Mounting:** Uses standard M3 screws for easy integration into CNC machines or 3D printers. * **Small Slot:** The 5mm slot is optimized for detecting thin metal "flags" or disk encoders. ---