TOTO100 RTP SLOT The slotted optical switch, sometimes known as opto switch or optical switch but not to be confused with the optical component, is a device comprising a photoemitter (e.g. LED) and a photodetector (e.g. photodiode) mounted in a single package so that the photoemitter normally illuminates the photodetector, but an opaque object can be inserted in a slot between them so as to break the beam. This device uses the same basic components as an opto-coupler, but is operated by manipulating the light path instead of the photoemitter input.|The Chronicles of Slot Booking