operator terminal A display screen and keyboard, for displaying monitoring output and taking in control input, specifically designed for the control and monitoring of the system
optical filter An optical component that selectively separates out light with one property (wavelength, polarization) and letting the rest pass (or vice versa)
order-picker An automatic system for selecting chosen objects from their individual storage locations in a warehouse to make up a given order
oscillator A device that produces an electronic output at a stable, predetermined frequency
oscilloscope Apparatus for measuring voltage, and plotting successive values against time on a monitor screen
overhead conveyor A system for supporting containers, and carried overhead on pulleys, organized as a continuous loop, for conveying material from one place to another (around a factory or warehouse, for example)
overhead crane A crane (for lifting and lowering heavy weights) that moves about (usually on tracks) above the workplace
oxygen analyzer Apparatus for measuring the relative abundance of oxygen in a sample of gas