Omron E3FB-RN21 Photoelectric Sensor
Omron E3FB-RN21 is an NPN retro-reflective photoelectric sensor with an MSR function and a sensing range from 0.1 to 4 m when used with the E39-R1S reflector. Its 624 nm red LED provides the optical beam, while opaque objects interrupt the returning light path to change the output state. The sensor operates from 10 to 30 VDC, consumes up to 25 mA, and uses an M12 connector for detachable machine wiring. Light-ON or Dark-ON can be selected by wiring, and a one-turn adjuster supports sensitivity setting. Within the E3FB Series, the E3FB-RN21 provides the NPN connector format. Reflector-based applications can explore MSR retro-reflective sensors available within Omron Sensing Range.
| Brand | Omron |
| Product | Photoelectric Sensors |
| Model Number | E3FB-RN21 |
Omron E3FB-RN21 Photoelectric Sensor – Technical Specifications
| Specification | Value |
|---|---|
| Sensing Method | Retro-reflective with MSR function |
| Sensing Distance | 0.1 to 4 m |
| Standard Sensing Object | Opaque: 75 mm dia.min. |
| Light Source | Red LED (624 nm) |
| Power Supply Voltage | 10 to 30 VDC (include voltage ripple of 10%(p-p) max.) |
| Output Configuration | NPN |
| Connection Method | M12 Connector |
| Current Consumption | 25 mA max. |
| Control Output | Load current: 100 mA max. (Residual voltage: 3 V max.), Load power supply voltage: 30 VDC max. |
| Operation Mode | Light-ON/Dark-ON selectable by wiring |
| Response Time | 0.5 ms |
| Sensitivity Adjustment | One-turn adjuster |
| Indicators | Operation indicator (orange) Stability indicator (green) |
| Ambient Illumination | Incandescent lamp: 3,000 lx max./ Sunlight: 10,000 lx max. |
| Ambient Temperature Range | Operating: -25 to 55°C/ Storage: -40 to 70°C (with no icing or condensation) |
| Ambient Humidity Range | Operating: 35 to 85%/ Storage: 35 to 95% (with no condensation) |
| Insulation Resistance | 20 MΩ min. at 500 VDC |
| Dielectric Strength | 1,000 VAC at 50/60 Hz for 1 min. between current-carrying parts and case |
| Vibration Resistance | Destruction: 10 to 55 Hz, 1.5 mm double amplitude 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 reverse polarity protection |
| Degree Of Protection | IEC: IP67, DIN 40050-9: IP69K |
| Material | Nickel-brass, PMMA, POM, Nickel-brass |
| Weight | Approx. 50 g/ Approx. 20 g |
The Omron E3FB-RN21 Photoelectric Sensor uses retro-reflective sensing with an MSR function across 0.1 to 4 m when used with the E39-R1S reflector. Its 624 nm red LED transmits light toward the reflector, while an opaque object crossing the optical path changes the NPN output state. The sensor operates from 10 to 30 VDC and consumes up to 25 mA. An M12 connector provides detachable electrical connection, while a one-turn adjuster supports sensitivity setting. Light-ON or Dark-ON operation can be selected by wiring. Load current is specified up to 100 mA, and response time is 0.5 ms. Orange operation and green stability indicators provide visual status. Nickel-brass, PMMA, and POM are among the specified materials, with IP67 and IP69K protection.
For an Omron NPN retro-reflective sensor requiring MSR functionality, M12 wiring, sensitivity adjustment, and sensing to 4 m, the corresponding model is the E3FB-RN21. Its configuration also fits searches for an Omron 4 m retro-reflective sensor, Omron M12 photoelectric sensor, and Omron NPN MSR sensor. For the corresponding NPN E3FB model using a 4 m retro-reflective arrangement with a pre-wired 2 m cable, see E3FB-RN11 2M.
