The **E3Z-R61** is a popular retro-reflective photoelectric sensor manufactured by Omron. It is widely used in industrial automation for detecting objects via an infrared light beam and a reflector. ### 1. Technical Specifications The following table highlights the core electronic and physical characteristics of the sensor: | Feature | Specification | | :--- | :--- | | **Sensing Method** | Retro-reflective (with MSR function) | | **Sensing Distance** | 100 mm to 4 m (using E39-R1S reflector) | | **Power Supply Voltage** | 12 to 24 VDC ±10% | | **Current Consumption** | 30 mA maximum | | **Output Type** | NPN Open Collector | | **Control Output** | Max 100 mA (at 26.4 VDC) | | **Response Time** | 1 ms (Operate or Reset) | | **Light Source** | Red LED (660 nm) | | **Connection** | Pre-wired cable (2 meters) | --- ### 2. Internal Electronic Structure The E3Z-R61 consists of several integrated electronic components that manage light emission and signal processing: * **Emitter (LED):** A high-intensity Red LED that pulses to reduce ambient light interference. * **Receiver (Photodiode):** A high-sensitivity diode that detects the reflected beam. * **MSR (Mirror Surface Rejection):** An internal optical filter system that allows the sensor to distinguish between the light reflected by the dedicated reflector and light reflected by shiny objects (like a tin can or stainless steel). * **Amplifier Circuit:** Boosts the weak signal from the photodiode to a level that can trigger the output transistor. * **Logic Circuit:** Handles the "Light-ON" or "Dark-ON" switching logic based on user selection. --- ### 3. Wiring Diagram (NPN Output) The sensor uses a standard 3-wire color code. Because it is an **NPN** type, the load is connected between the positive supply and the black output wire. ```text [ Brown ] Positive (+V) 12-24VDC [ Blue ] Negative (0V) [ Black ] Control Output (NPN) ``` --- ### 4. Adjustments and Indicators * **Sensitivity Potentiometer:** A one-turn trimmer used to adjust the threshold for object detection. * **Operation Indicator (Orange):** Lights up when the output is triggered. * **Stability Indicator (Green):** Lights up when the received light level is stable (sufficiently above or below the threshold), ensuring reliable operation even if the lens gets slightly dirty. ---