Omron E3RA-RP21 Photoelectric Sensor
Omron E3RA-RP21 is a PNP retro-reflective photoelectric sensor with an MSR function for object sensing across 0.1 to 3 m. Its 624 nm red LED establishes the optical path toward a compatible reflector, while the PNP output transfers the switching state to PLC inputs and machine-control circuitry. The sensor operates from 10 to 30 VDC, supports a load current up to 100 mA, and provides a 0.5 ms response time. Light-ON or Dark-ON operation can be selected by wiring, and an M12 connector supports detachable connection. Within the E3RA Series, the E3RA-RP21 provides the PNP retro-reflective option. Related MSR retro-reflective sensors are available across Omron Sensors.
| Brand | Omron |
| Product | Photoelectric Sensors |
| Model Number | E3RA-RP21 |
Omron E3RA-RP21 Photoelectric Sensor – Technical Specifications
| Specification | Value |
|---|---|
| Sensing Method | Retro-reflective with MSR function |
| Sensing Distance | 0.1 to 3 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 | PNP |
| Connection Method | M12 Connector |
| Current Consumption | 25 mA max. |
| Control Output | Load current: 100 mA max. (Residual voltage: 2 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 | ABS, PMMA, POM, POM |
| Weight | Approx. 20 g/ Approx. 10 g |
The Omron E3RA-RP21 Photoelectric Sensor uses retro-reflective sensing with an MSR function across a specified range of 0.1 to 3 m. Its 624 nm red LED establishes an optical path toward the reflector, while the PNP output transfers the switching state to compatible PLC inputs and machine-control circuitry. The sensor operates from 10 to 30 VDC and consumes up to 25 mA. Load current is specified at 100 mA maximum, with load supply voltage up to 30 VDC. Light-ON or Dark-ON operation can be selected by wiring, and a one-turn adjuster supports sensitivity setting. The M12 connector provides detachable electrical connection. Response time is specified at 0.5 ms, while orange operation and green stability indicators provide visual information during setup.
For an Omron PNP retro reflective photoelectric sensor requiring MSR and 0.1 to 3 m sensing, the relevant model is the E3RA-RP21. The stated target is an opaque object with a minimum diameter of 75 mm. Ambient-light resistance reaches 3,000 lx under incandescent light and 10,000 lx under sunlight. Operating temperature extends from -25 to 55°C, with storage from -40 to 70°C without icing or condensation. Power-supply reverse polarity, output short-circuit, and output reverse-polarity protection are included. Its specification also suits searches for an Omron 3 m PNP sensor and Omron MSR photoelectric sensor. For an E3RA PNP model using a 15 m through-beam sensing method, see E3RA-TP21.
