### Overview of the E3JK-R4M22M The **E3JK-R4M22M** is a high-performance, long-distance photoelectric sensor manufactured by Omron. It is a **Retro-reflective** type sensor, meaning it emits a light beam toward a reflector and detects an object when the beam is interrupted. --- ### Technical Specifications The following table highlights the core electronic and physical characteristics: | Feature | Specification | | :--- | :--- | | **Sensing Method** | Retro-reflective (with MSR function) | | **Sensing Distance** | 0.1 to 6 meters (when using E39-R1 reflector) | | **Supply Voltage** | 24 to 240 VAC / 24 to 240 VDC (Multi-voltage) | | **Output Type** | Relay Output (SPDT - Single Pole Double Throw) | | **Switching Capacity** | 3A at 250 VAC (Resistive load) | | **Response Time** | 20 ms maximum | | **Light Source** | Red LED (624 nm) | | **Operating Mode** | Light-ON / Dark-ON (Selectable via switch) | --- ### Key Electronic Components & Functions #### 1. Multi-Voltage Power Supply One of the most significant electronic features of this model is its ability to accept a wide range of voltages (**24-240V AC or DC**). This is achieved through an internal switching regulator circuit that stabilizes the voltage for the sensor's internal logic. #### 2. MSR (Mirror Surface Rejection) This sensor includes a polarizing filter. Electronics within the sensor distinguish between the light reflected from a **reflector** (which rotates the light's polarization) and light reflected from a **shiny object** (which does not). This prevents false triggers from stainless steel or mirror-like surfaces. #### 3. Relay Output (SPDT) Unlike NPN or PNP transistor sensors, the E3JK-R4M22M uses a mechanical relay. * **Electronic benefit:** It provides potential-free (dry) contacts, allowing you to switch a different voltage than the sensor's supply voltage. * **Durability:** The relay is rated for 50,000,000 operations (mechanical). #### 4. Diagnostic Indicators The sensor housing contains two main LEDs for electronic troubleshooting: * **Operation Indicator (Orange):** Lights up when the output is active. * **Stability Indicator (Green):** Lights up when the received light intensity is sufficient to ensure stable operation, helping with alignment. --- ### Wiring Configuration The sensor typically uses a 5-wire cable system: | Wire Color | Function | Description | | :--- | :--- | :--- | | **Brown / Blue** | Power Supply | 24-240V AC or DC (Non-polar) | | **White** | Relay Common (COM) | The shared terminal for the relay | | **Black** | Normally Open (NO) | Contact closes when triggered | | **Gray** | Normally Closed (NC) | Contact opens when triggered | ---