The **PMS-C-R** generally refers to a specific series of **Photoelectric Sensors** (often categorized under retro-reflective or diffuse sensors) used in industrial automation for object detection. Below is a breakdown of the electronic components, technical specifications, and internal architecture common to these sensors. --- ### 1. Core Electronic Components A photoelectric sensor like the PMS-C-R operates by converting light signals into electrical signals. | Component | Function | | :--- | :--- | | **Emitter (LED)** | Usually an Infrared (IR) or Red light-emitting diode that pulses to reduce ambient light interference. | | **Receiver (Photodiode/Transistor)** | A light-sensitive element that detects the reflected beam. | | **Modulator/Oscillator** | Controls the frequency of the Emitter's pulses to ensure the receiver only reacts to its own light source. | | **Amplifier & Comparator** | Boosts the weak signal from the receiver and compares it against a threshold to trigger a logic state. | | **Output Stage (NPN/PNP)** | A switching transistor that allows the sensor to interface with a PLC or relay. | --- ### 2. Technical Specifications The "C" typically denotes a **Cable** connection, and "R" often signifies **Retro-reflective** or a specific **Relay/Range** characteristic. | Feature | Typical Value / Description | | :--- | :--- | | **Supply Voltage** | 10–30V DC (Standard for industrial PLC systems) | | **Output Type** | NPN or PNP (Open Collector) | | **Operating Mode** | Light-ON / Dark-ON (Selectable via wire or switch) | | **Response Time** | < 1ms to 2ms | | **Current Consumption** | Max 30mA | | **Protection Circuitry** | Reverse polarity, short circuit, and surge protection. | --- ### 3. Connection and Wiring The electronic interface usually consists of a 3-wire or 4-wire configuration: * **Brown (V+):** Positive power supply (12-24V DC). * **Blue (0V):** Ground/Negative. * **Black (OUT):** The switching signal sent to the controller. * **White (Mode/Control):** Sometimes used to toggle between Light-ON (outputs signal when light is received) and Dark-ON (outputs signal when light is blocked). --- ### 4. Working Principle (Retro-Reflective) 1. **Emission:** The internal circuit triggers the LED to send a beam toward a reflector. 2. **Detection:** The light bounces back to the photodiode. 3. **Interruption:** When an object passes between the sensor and the reflector, the light circuit is broken. 4. **Logic Switch:** The comparator detects the drop in current and triggers the output transistor (NPN or PNP) to change state (e.g., from 0V to 24V). ---