## E3F2-R4B4 Photoelectric Sensor Overview The **E3F2-R4B4** is a cylindrical M18 threaded photoelectric sensor commonly used in industrial automation for object detection. It belongs to the E3F2 series, typically manufactured by brands like Omron (or compatible alternatives). --- ### 1. Technical Specifications The following table outlines the primary electrical and physical characteristics of the device: | Feature | Specification | | :--- | :--- | | **Sensing Method** | Retro-reflective (Requires a reflector) | | **Sensing Distance** | 0.1 to 4 meters (depending on reflector type) | | **Output Type** | PNP (Source) | | **Output Mode** | Selectable Light-ON / Dark-ON (usually wired) | | **Supply Voltage** | 10 to 30 VDC | | **Current Consumption** | 30 mA maximum | | **Load Current** | 100 mA maximum | | **Response Time** | 2.5 ms maximum | | **Housing Material** | Plastic (ABS) or Brass-Nickel plated | | **Protection Rating** | IP67 (Dust and water-resistant) | --- ### 2. Electronic Internal Structure The E3F2-R4B4 operates using three main internal stages: 1. **Emitter Stage:** Uses an Infrared LED (or visible Red LED) to pulse light toward a reflector. 2. **Receiver Stage:** A phototransistor detects the reflected light. It includes a specialized IC to filter out ambient light and noise. 3. **Output Stage:** A **PNP Transistor** acts as a switch. When triggered, it connects the Load wire to the positive supply voltage ($V_{CC}$). --- ### 3. Wiring Diagram (Color Coding) Standard industrial color coding is used for the 3-wire DC connection: | Wire Color | Function | Description | | :--- | :--- | :--- | | **Brown** | +VCC | Positive power supply (10-30V) | | **Blue** | 0V / GND | Negative power supply | | **Black** | Output | PNP Signal (Connected to Load) | #### Connection Logic: * **PNP Output:** The sensor provides a "High" signal. The load should be connected between the **Black (Output)** wire and the **Blue (GND)** wire. --- ### 4. Key Electronic Features * **Short-Circuit Protection:** The sensor is equipped with internal circuitry to prevent damage if the output is accidentally grounded. * **Reverse Polarity Protection:** Prevents damage if the Brown and Blue wires are swapped during installation. * **Mutual Interference Prevention:** Allows two sensors to be mounted close to each other without their light beams triggering the other's receiver. ---