Panasonic CX-421 Reflective Diffuse Optical Sensor

The Panasonic Sunx CX-421 is a compact diffuse-reflective photoelectric sensor designed to detect opaque, translucent, or transparent surfaces at up to 300 mm (11.811 in) with an 860 nm infrared emitter. It operates from a DC supply of 12–24 V and draws about 13 mA, delivering a 100 mA max open-collector output (NPN for CX-421; PNP variants available as CX-421-P) with a 30 V maximum applied voltage. Sensing distance, hysteresis (about 15% of range), repeatability (≤1 mm), and response time (≤1 ms) are specified for diffuse reflective sensing, with the range defined for white non-glossy paper in the reference datasheet. Protection IP67, ambient temperature -25 to +55°C, and humidity 35–85% RH help ensure reliability in industrial environments; enclosure is PBT with an acrylic lens and indicator cover, and the unit weighs about 50 g net (60 g gross). The standard cable is 2 m long (0.2 mm2, 3-core; emitter is 2-core) and there are variant options such as CX-421-P (PNP output) and CX-421-J (M12 pigtailed) to fit different control schemes. This sensor is commonly used for end-of-line presence checks, packaging, and automation tasks that require non-contact detection.