Omron E3S-DCN21 Photoelectric Sensor
The Omron E3S-DCN21 Photoelectric Sensor is a Color Mark Diffuse-reflective (mark detection) with 10±3 mm sensing distance, NPN output, and M12 connector for precise mark detection. It operates on a 10 to 30 VDC power supply and consumes 960 mW power, designed under the Omron automation portfolio within the Omron Photoelectric Sensors category and the Omron E3S Series. Featuring Red (635 nm), Green (525 nm), and Blue (465 nm) LED light sources, it provides 50 μs response time, ON when mark detected operation, 100 mA load current, and IP67 protection for reliable performance in industrial applications.

| Brand | Omron |
| Product | Photoelectric Sensors |
| Model Number | E3S-DCN21 |
Omron E3S-DCN21 Photoelectric Sensor – Technical Specifications
| Specification | Value |
|---|---|
| Sensing Method | Diffuse-reflective (mark detection) |
| Sensing Distance | 10 ±3 mm (White paper 10 ×10 mm) |
| Light Source | Red LED (635 nm), Green LED (525 nm), Blue LED (465 nm) |
| Power Supply Voltage | 10 to 30 VDC (Ripple (p-p) 10% max.) |
| Output Configuration | NPN |
| Connection Method | M12, 4-pin connector |
| Power Consumption | 960 mW max. |
| Control Output | Load current: 100 mA max. (30 VDC max.) |
| Operation Mode | ON when mark is detected. |
| Response Time | Operate or reset: 50 μs max. for each (2-point teaching mode), 150 μs max. for each (1-point teaching mode) |
| Sensitivity Adjustment | Teaching method |
| Ambient Illumination | Incandescent lamp: 3,000 lx max. |
| Ambient Temperature Range | Operating: −10 to 55°C; Storage: −25 to 70°C (with no icing or condensation) |
| Ambient Humidity Range | Operation: 35% to 85%, Storage: 35% to 95% (with no condensation) |
| Insulation Resistance | 20 MΩ min. (at 500 VDC) |
| Dielectric Strength | 1,000 VAC, 50/60 Hz for 1 min |
| Vibration Resistance | Destruction: 10 to 55 Hz with double amplitude of 1.5 mm for 2 hours each in X, Y, and Z directions |
| Shock Resistance | Destruction: 500 m/s2 3 times each in X, Y, and Z directions |
| Protection Circuits | Power supply reverse polarity protection, output short-circuit protection and output incorrect connection protection |
| Degree Of Protection | IEC 60529 IP67 |
| Material | Diecast zinc (nickel-plated brass), Methacrylic resin (PMMA), ABS, Elastomers, Diecast zinc (nickel-plated brass) |
| Weight | Approx. 370 g/approx. 320 g |
Engineered by Omron, the E3S-DCN21 Photoelectric Sensor offers mark detection accuracy using red, green, and blue LED light sources with a sensing distance of 10 ±3 mm. It supports 2-point and 1-point teaching modes, with response times of 50 µs and 150 µs respectively—making it one of the fastest in its class for detecting print registration marks and subtle contrast variations on packaging or labels.
With a durable diecast zinc housing, this sensor is built to withstand tough conditions, meeting IP67 protection standards against dust and water. It runs on a 10 to 30 VDC power supply, delivers NPN output, and features protection circuits for reverse polarity, output short-circuit, and incorrect connections. Its M12 connector, compact footprint, and reliable mark detection make the Omron E3S-DCN21 a trusted choice across packaging, printing, and labeling systems.




