Omron E3F-DS30B2 Photoelectric Sensor, NPN NC, DC 6–36V, 200mA, 7–30 cm Detection Range

The E3F-DS30B2 features a Normally Closed (NC) NPN output. In its idle state (no object detected), the output transistor is ON, sinking current to ground. When an object is detected within range, the output switches OFF (opens). This is the inverse of a Normally Open (NO) output and is often used for fail-safe circuits where a broken wire or power loss is interpreted as a detection event.

The sensor has a sensitivity adjustment potentiometer, typically located on the side or rear of the housing. Use a small screwdriver to turn the potentiometer. Clockwise rotation usually increases sensitivity and thus the maximum detection distance, while counter-clockwise rotation decreases it. Test the setting with your target object under actual installation conditions for optimal performance.

Yes, but you must use a voltage divider or an optocoupler interface for safe connection. The sensor's output is an NPN open-collector that sinks up to 200mA to ground. Connect the sensor's output wire to your digital input pin via a pull-up resistor (e.g., 10kΩ to 3.3V or 5V). When the sensor detects an object, the output opens, and the input pin reads HIGH via the pull-up. Ensure the sensor's power supply (6-36V) is separate from your microcontroller's logic voltage.

For a typical PLC DC sinking input module: Connect the sensor's brown wire (+V) to your DC power supply positive (within 6-36V). Connect the black wire (output) to the PLC's digital input terminal. Connect the blue wire (0V) to the power supply negative and the PLC's common terminal. The PLC input will be active (ON) when no object is present (NC logic) and turn OFF when an object is detected.

The rated 30 cm maximum is for a standard white, matte-finished object (90% reflectivity). Detection distance decreases with darker colors, glossy surfaces (which can reflect light away), or non-orthogonal angles. Environmental factors like dust, fog, or strong ambient light (sunlight) can also reduce reliable range. For consistent performance, test with your actual target object and consider derating the maximum operational distance.