A method for optically communicating, from a user to a laser tracker, a command to control tracker operation includes providing a rule of correspondence between commands and temporal patterns, and selecting by the user a first command. Also, projecting a first light from the tracker to the retroreflector, reflecting a second light from the retroreflector, the second light being a portion of the first light, obtaining first sensed data by sensing a third light which is a portion of the second light, creating by the user, between first and second times, a first temporal pattern which includes a decrease in the third optical power followed by an increase in the third optical power, the first temporal pattern corresponding to the first command, determining the first command based on processing the first sensed data per the rule of correspondence and executing the first command with the tracker.