## Technical Overview of E3F2-R4B4-M The **E3F2-R4B4-M** is a high-performance cylindrical photoelectric sensor manufactured by **Omron**. It belongs to the E3F2 series, designed for industrial automation tasks involving object detection. --- ### 1. Key Technical Specifications | Feature | Specification | | :--- | :--- | | **Sensing Method** | Retro-reflective (Requires a reflector) | | **Sensing Distance** | 0.1 to 4 Meters | | **Output Type** | PNP Open Collector | | **Output Mode** | Light-ON / Dark-ON (Selectable via wiring) | | **Supply Voltage** | 10 to 30 VDC | | **Housing Material** | Brass-nickel plated (Metal) | | **Connection Method** | M12 Connector (4-pin) | | **Light Source** | Infrared LED | --- ### 2. Electronic Components & Internal Logic The sensor functions through a sophisticated internal circuit that manages light emission and signal processing: * **Emitter Section:** Contains an **Infrared (IR) LED** that pulses light at a specific frequency to avoid interference from ambient light (like sunlight or overhead lamps). * **Receiver Section:** A **Photodiode** paired with an integrated circuit (IC) that filters out everything except the specific frequency of the pulsed IR light. * **PNP Output Stage:** The "B4" in the model name indicates a **PNP transistor** output. * When triggered, it connects the load to the positive supply voltage ($V_{cc}$). * It supports a maximum current of approximately **100mA**. * **Protection Circuitry:** Includes reverse polarity protection and short-circuit protection to prevent damage during installation errors. --- ### 3. Wiring Configuration Since this is the **-M** (M12 Plug) version, the pinout follows standard industrial colors: ```text Pin 1 (Brown): +V (10-30 VDC) Pin 2 (White): Control Input (L-ON/D-ON Selection) Pin 3 (Blue): 0V (Ground) Pin 4 (Black): Output (PNP) ``` --- ### 4. Operational Principle (Retro-reflective) 1. The sensor emits an IR beam. 2. The beam hits a **reflector** (like the E39-R1) and returns to the sensor's receiver. 3. When an **opaque object** passes between the sensor and the reflector, the beam is broken. 4. The internal PNP transistor changes state, sending a signal to the connected PLC or relay.