## Technical Overview: E3JM-R4S4T Photoelectric Sensor The **E3JM-R4S4T** is a high-performance, rectangular photoelectric sensor manufactured by Omron. It belongs to the E3JM series, which is known for its versatility in power supply options and robust output capabilities. --- ### 1. Key Electronic Specifications The "electronic parts" of this sensor define its power handling, sensing logic, and output interface. | Feature | Specification | | :--- | :--- | | **Sensing Method** | Retro-reflective (requires a reflector) | | **Sensing Distance** | Up to 4 meters (with E39-R1 reflector) | | **Supply Voltage** | 12 to 240 VDC or 24 to 240 VAC (Universal) | | **Output Type** | Relay Output (SPDT) | | **Switching Capacity** | 3A at 250 VAC (Resistive Load) | | **Power Consumption** | 3W maximum | | **Response Time** | 20 ms (Maximum) | | **Light Source** | Infrared LED | --- ### 2. Internal Electronic Components & Functions #### A. Universal Power Supply Block One of the most significant electronic features of this model is the built-in switch-mode power circuitry. It can accept a wide range of voltages (both AC and DC) without needing manual adjustment, making it compatible with global industrial grids. #### B. Timer Function (The "T" Suffix) The **"T"** in the model name indicates the inclusion of an **onboard timer**. * **Adjustment:** Typically features a potentiometer under the wiring cover. * **Modes:** It usually supports ON-delay, OFF-delay, and One-shot timing functions. * **Time Range:** Adjustable from 0.1 to 5 seconds. #### C. Relay Output Interface Unlike NPN/PNP transistor outputs, the E3JM-R4S4T uses a **Mechanical Relay (SPDT)**. * **Advantage:** It can switch high-current AC loads directly. * **Isolation:** The output circuit is galvanically isolated from the power supply circuit. --- ### 3. Wiring Configuration The sensor features a terminal block for connections. Below is the standard pinout logic: | Terminal | Function | Description | | :--- | :--- | :--- | | **1 & 2** | Power Supply | Connect 12-240V DC or 24-240V AC | | **3** | Relay COM | Common terminal for the relay | | **4** | Relay NC | Normally Closed contact | | **5** | Relay NO | Normally Open contact | --- ### 4. Operational Indicators The electronic assembly includes two primary LED indicators for diagnostic purposes: * **Light Indicator (Red):** Lights up when the receiver is receiving light. * **Stability Indicator (Green):** Lights up when the light level is stable (well above the threshold), ensuring the sensor is not on the edge of failing due to dust or misalignment. ---