These targets may take the form of retro-reflective tape or inexpensive bicycle reflectors. It may be oriented in any position as long as the projected laser beam strikes the intended target at the intended moment of measurement. There are four modes of operation possible via the host computer. The first mode utilizes the internal factory distance calibration, allowing on to perform distance measurements relative to the front, middle bracket, or rear of the unit as desired. The second mode of operation allows the user to define the initial distance between the unit and the target.
Subsequent measurements utilize that distance as the calibrated reference.
In the third mode of operation, the initial position is defined as zero and all subsequent measurements are made relative to that position. The fourth mode of operation is meant for applications that require very fast, continuous tracking of the relative movement the target over time. In this mode, the unit can either return a distance calibrated with respect to an input initial position of the target, or it can return the net distance the target has moved since the measuring sequence was initiated. For modes 1 through 3, the averaging time of each measurement can be set between approximately 40 milliseconds and 1 second, and the repetition rate of the measurements can be sent as fast as 10 Hz. Alternatively, the repetition rate can be set to zero, in which case only a single measurement is performed.