Omron E3T-SL21 2M Photoelectric Sensor
Omron E3T-SL21 2M is an ultracompact limited-reflective photoelectric sensor designed for short-range object sensing from 5 to 30 mm. A red LED directs light toward the target, while the built-in amplifier processes the returned optical signal. Its NPN output transfers the switching state to compatible PLC inputs and control circuits, and Light-ON operation defines the specified logic. The sensor operates from 12 to 24 VDC, consumes up to 20 mA, and includes a 2 m pre-wired cable. The square body supports mounting in compact equipment. Within the E3T Series, the E3T-SL21 2M provides the 30 mm NPN option. Related 30 mm reflective sensors are available across Omron Industrial Sensor Products.

| Brand | Omron |
| Product | Photoelectric Sensors |
| Model Number | E3T-SL21 2M |
Omron E3T-SL21 2M Photoelectric Sensor - Technical Specifications
| Specification | Value |
|---|---|
| Sensing Method | Limited Reflective |
| Shape | Square type |
| Sensing Distance | 5 to 30 mm |
| Power Supply Voltage | 12 to 24 VDC |
| Output Configuration | NPN |
| Connection Method | Pre-wired cable length 2m |
| Current Consumption | 20 mA max |
| Light Source (Wavelength) | Red LED |
| Operation Mode | Light-ON |
| Response Time | 1 ms max. |
| Degree Of Protection | IP67 |
| Material | Polybutylene terephthalate |
| Material Lens | Denatured Polyarylate |
| Weight | 20g |
The Omron E3T-SL21 2M Photoelectric Sensor uses limited-reflective sensing across a short 5 to 30 mm range in an ultracompact square body. A red LED directs light toward the target, while the built-in amplifier processes the returned optical signal. The NPN output transfers the switching state to compatible PLC inputs and machine-control circuitry, and Light-ON operation defines the specified output logic. The sensor operates from 12 to 24 VDC and consumes up to 20 mA. Operate or reset time is specified at 1 ms max., and a 2 m pre-wired cable provides the electrical connection. The short working range supports close-position sensing where mounting space is limited.
For an Omron limited reflective NPN sensor requiring 5 to 30 mm sensing and Light-ON operation, the relevant model is the E3T-SL21. Polybutylene terephthalate is listed for the housing and denatured polyarylate for the optical section. IP67 protection is specified, with approximate weight of 20 g. Its configuration also suits searches for an Omron 30 mm reflective sensor and Omron compact NPN photoelectric sensor. The 1 ms response supports small-part presence and position confirmation in compact equipment. For the related Dark-ON version using the same output type and sensing range, see E3T-SL22 2M.


