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LSC contains two unit systems. The first set of units, positionDeviceUnits, velocityDeviceUnits, and accelerationDeviceUnits, the device unit system, is intended for you, the class writer. You are free to specify any units you like for these properties, so long as you then provide the "raw" device quantities/properties in those units. For example, you must implement positionAbsoluteRaw to report its values in positionDeviceUnits. Typically, you would set the device this unit system to agree with the unit system used by the device hardware.
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