A Manual Override Beam was an advanced system used by the Zentraedi as a means of controlling their forces in the field. They were typically deployed on flagship class vessels and were able to override the navigation systems of their mecha. This allowed Zentraedi commanders to forcibly force their units to retreat back to their vessels and was used during unauthorized attacks.
During the First Robotech War, Khyron indulged in his persona vendetta against the SDF-1 where he launch a devastating assault on the Human ship. This attack was not authorized by Commander Breetai, who angrily used a Manual Override Beam to recall not only Khyron but his entire assault force, thus breaking them away from the battle. The use of the beam narrowly saved the life of Rick Hunter, who was engaged in a fight against Khyron. (Macross Saga: Sweet Sixteen)