The QS18 Expert opposed-mode sensor with IO-Link is a compact photoelectric sensor with infrared and visible beam emitter/receiver pairs with a range of 20 m (66 ft). Ambient light immunity prevents unintentional triggering and keeps the sensor from being tricked by ambient light sources, such as a lightbulb, flashlight or other light-emitting industrial sensors. Optical synchronization allows each sensor to be set to one of three frequency channels so that three sensor pairs can be mounted side by side with no cross talk. Teach and Set methods ensure optimal gain and threshold for all applications, especially for high-speed or partial beam block (low-contrast) applications.