### Overview of the E3JM-R4R4-US The **E3JM-R4R4-US** is a high-performance photoelectric sensor manufactured by Omron. It is part of the E3JM series, which is known for its versatility, built-in power supply, and relay output capabilities. This specific model is a **Retro-reflective** sensor. --- ### Technical Specifications Below are the primary electronic and physical specifications for the E3JM-R4R4-US: | Feature | Specification | | :--- | :--- | | **Sensing Method** | Retro-reflective (requires a reflector) | | **Sensing Distance** | Up to 4 Meters (using E39-R1 reflector) | | **Supply Voltage** | 12 to 240 VDC or 24 to 240 VAC (Multi-voltage) | | **Output Type** | Relay Output (SPDT - Single Pole Double Throw) | | **Power Consumption** | 2 W max. / 3 VA max. | | **Response Time** | 20 ms max. | | **Light Source** | Infrared LED | | **Enclosure Rating** | IP66 (Water and dust resistant) | --- ### Key Electronic Components & Functions #### 1. Multi-Voltage Power Supply One of the standout features of this sensor is its internal power conversion circuit. It can accept a wide range of input voltages (12V to 240V DC or 24V to 240V AC), making it compatible with almost any industrial power grid without needing a separate DC power supply. #### 2. Relay Output (SPDT) Unlike NPN/PNP sensors that output a small voltage signal, the E3JM-R4R4-US uses a physical relay. * **Capacity:** 3A at 250 VAC. * **Function:** It acts as a dry contact switch, allowing you to directly control high-load devices like motors, sirens, or large contactors. #### 3. Timer Functions (The "4" in the suffix) The "R4" designation typically indicates that this model includes built-in timing functions. These are adjustable via internal DIP switches/potentiometers: * **ON-delay:** Delays the output after an object is detected. * **OFF-delay:** Keeps the output active for a set time after the object has left. * **One-shot:** Provides a pulse of a specific duration regardless of how long the object stays in front of the sensor. #### 4. Light-ON / Dark-ON Selectability The sensor contains a switch that allows the user to define when the relay should trigger: * **Light-ON:** Relay activates when the light beam returns from the reflector (no object present). * **Dark-ON:** Relay activates when the light beam is broken (object is present). --- ### Wiring Configuration The unit features a terminal block for easy wiring. The typical pinout includes: ```text Terminal 1 & 2: Power Supply Input (AC or DC) Terminal 3: Relay Common (COM) Terminal 4: Relay Normally Closed (NC) Terminal 5: Relay Normally Open (NO) ``` ---