The **E3JK-R2M1** is a popular high-performance photoelectric sensor manufactured by Omron. It is a **Retro-reflective** type sensor, meaning it emits a light beam toward a reflector and detects objects when the beam is interrupted. --- ## 1. Technical Specifications The following table summarizes the key electronic and physical characteristics of the E3JK-R2M1: | Parameter | Specification | | :--- | :--- | | **Sensing Method** | Retro-reflective (requires a reflector) | | **Sensing Distance** | Up to 2.5 meters (with E39-R1 reflector) | | **Supply 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 | | **Light Source** | Pulse Modulated Infrared LED | | **Response Time** | 30 ms maximum | | **Ambient Temperature** | -25°C to 55°C | --- ## 2. Main Components and Working Principle ### Internal Electronic Block The device consists of four primary electronic stages: 1. **Emitter:** An Infrared (IR) LED that pulses light to prevent interference from ambient light sources. 2. **Receiver:** A photodiode or phototransistor tuned to the specific frequency of the emitter. 3. **Amplifier/Logic Circuit:** Processes the signal from the receiver to determine if the beam is blocked. 4. **Relay Output:** A mechanical relay that opens or closes a circuit based on the detection state. ### Wiring Configuration The E3JK-R2M1 uses a 5-wire system: * **Brown & Blue:** Power supply (Universal AC/DC). * **White:** Relay Common (COM). * **Black:** Normally Open (NO) contact. * **Gray:** Normally Closed (NC) contact. --- ## 3. Key Features * **Universal Voltage:** One of its strongest features is its ability to operate on almost any standard power supply (Multi-voltage). * **Built-in Relay:** It can directly switch AC loads (like a motor or a large lamp) without needing an external PLC or transistor interface. * **Long Sensing Range:** Ideal for conveyor belts and garage door safety systems. * **IP64 Rated:** Protected against dust and splashing water, making it suitable for industrial environments. ---