Spec Recap & Key Ratings
The Omron E3T-SL11M is an ultracompact convergent-reflective photoelectric sensor with built-in amplifier, NPN output. Sensing distance is fixed at 5 to 15 mm on a 50×50 mm white paper target; hysteresis stays within 2 mm. The red LED (650 nm) source and convergent beam cut out background reflections, so it's sized for short-range presence detection where ambient light or glossy backgrounds would trip a diffuse sensor. Control output is open-collector NPN rated 26.4 VDC max and 50 mA max; residual voltage is 2 V at 10–50 mA, dropping to 1 V below 10 mA. That fits standard 24 VDC PLC inputs. Response time is 1 ms max, adequate for high-speed part counting or edge detection on small parts. Power supply is 12 to 24 VDC ±10% with 20 mA max consumption. Built-in protection circuits cover reverse polarity on power supply and output, output short-circuit, and mutual interference prevention.
Convergent-reflective sensing means the emitter and receiver are focused on a single point 5–15 mm in front of the lens. The sensor ignores objects closer or farther; mounting distance is critical. Use a bracket that maintains the 5–15 mm gap to the target. The small hysteresis (2 mm max) gives repeatable switch points for precision registration or timing.