Capstan Tracking Logic. Control track or control track, a control signal consisting of a series of pulses that are recorded on a longitudinal track of the tape is recorded on this track. The unit of this signal is the frame (1/25 second).

The usefulness of this signal is the adjustment of the servomechanisms of a magnetoscope so that it maintains a perfect relationship between the video heads and the movement of the tape during recording so that it is the same as during playback.

The CTL is used to monitor and synchronize the rotation phase of the head carrier drum and the belt transport phase. Video heads scan the tape, following the same pattern during playback and recording.

Synchronization pulses are recorded image by image on a separate track of the video. Counting individual pulses, the CTL can calculate a length of time, this is what is used in most domestic formats to show a duration.