What this sensor is and where it fits
The Omron E3T-FD11 is a reflective diffuse photoelectric sensor with a 650 nm red LED light source and an NPN open-collector output configured for Light-ON operation. It detects objects by sensing reflected light from the target at a maximum distance of 0.197 mm — a very short range that suits close-proximity part-present or edge-detection tasks on a conveyor or pick-and-place station. The 1 ms response time keeps up with moderate line speeds without missing targets.
IP67 and temperature — what the ratings mean for the panel
Rated IP67, the E3T-FD11 is dust-tight and can handle temporary immersion — think washdown in a food-packaging area or a damp outdoor enclosure. The operating temperature range of -25°C to 55°C covers conditioned factory floors and mild outdoor cabinets, but not freezer lines or oven-adjacent zones. Supply is 12 VDC nominal; the NPN Light-ON output pulls low when the target is detected, so verify the PLC input card expects a sinking signal.
How it compares to the E3T-CD13 2M
If you are cross-shopping the E3T-CD13 2M, the key difference is output type: the E3T-FD11 uses NPN Light-ON, while the E3T-CD13 2M uses PNP Light-ON. Both are reflective diffuse sensors in the E3T series with IP67 and the same temperature range, but the E3T-CD13 2M has a 500 ms response time — slower — and uses an infrared (870 nm) LED instead of the red 650 nm source. The sensing distance on the E3T-CD13 2M is 0.118 mm, even shorter. Wiring compatibility depends on whether your PLC input card expects a sinking (NPN) or sourcing (PNP) signal — swapping between them may require a pull-up or pull-down resistor or a logic-level converter.