The **E3B2-R5M4D-US** is a legacy industrial photoelectric sensor manufactured by Omron. It is a **Retro-reflective** sensor, meaning it emits a beam of light towards a reflector and triggers when an object breaks that beam. --- ## Technical Specifications Below are the core electronic and operational parameters for this model: | Feature | Specification | | :--- | :--- | | **Sensing Method** | Retro-reflective (requires a reflector) | | **Sensing Distance** | Up to 5 meters (approx. 16.4 ft) | | **Supply Voltage** | Multi-voltage: 24 to 240 VAC or 12 to 240 VDC | | **Output Type** | Relay Output (SPDT - Single Pole Double Throw) | | **Switching Capacity** | 3A at 250 VAC (Resistive Load) | | **Light Source** | Infrared LED | | **Response Time** | 20 ms maximum | | **Operation Mode** | Light-ON / Dark-ON (Selectable via switch) | | **Protection Rating** | IP66 (Dust-tight and water-resistant) | --- ## Key Components & Internal Electronics ### 1. Power Supply Circuit One of the defining features of the E3B2 series is its **universal power supply**. Internally, it contains a bridge rectifier and a voltage regulator that allows it to accept a wide range of AC and DC inputs without needing a separate power converter. ### 2. The Optical System * **Emitter:** An Infrared (IR) LED that pulses light to reduce interference from ambient light (sunlight or room lighting). * **Receiver:** A phototransistor tuned specifically to the frequency of the IR emitter. * **Lens:** Specialized optics designed to focus the beam over a 5-meter range. ### 3. Relay Output (Electromechanical) Unlike modern sensors that use NPN/PNP transistors, the **R5M4D** suffix indicates a **relay output**. * **Advantage:** It can switch high-current AC loads directly. * **Internal Component:** A mechanical SPDT relay that provides physical "Dry Contacts" (Common, Normally Open, Normally Closed). ### 4. Adjustments and Indicators * **Sensitivity Potentiometer:** Allows the user to fine-tune the threshold to account for dusty environments or semi-transparent objects. * **Operation Switch:** A small internal slide switch to toggle between **Light-ON** (relay energizes when the beam is clear) and **Dark-ON** (relay energizes when the beam is blocked). * **LED Indicators:** Usually features a Red LED for "Output Status" and sometimes a Green LED for "Stability" (indicating the signal strength is sufficient). --- ## Wiring Configuration Typical wiring for the E3B2-R5M4D-US involves five terminals: 1. **Terminals 1 & 2:** Power Input (24-240V AC/DC, non-polarized). 2. **Terminal 3:** Relay Common (COM). 3. **Terminal 4:** Normally Closed (NC). 4. **Terminal 5:** Normally Open (NO). --- ## Application Note Because this model uses a mechanical relay, it has a finite mechanical life (usually around 50 million operations) and a slower response time (20ms) compared to solid-state sensors. It is best suited for conveyor counting, gate automation, and presence detection where high-speed switching is not required.