These measure distances precisely and without contact, using red or laser light. They are characterised by long ranges and high resolution. Programmable parameters or teach-in provide easy handling. Distance sensors have serial interfaces, as well as SSI for further external processing. They can be coupled to Profibus, Interbus-S and DeviceNet-Bus. Their areas of application extend from the positioning of cranes, automated guided vehicles, and storage and retrieval devices, through the monitoring of filling levels and regulation of slack, to the detection of the smallest objects in the µm-range.