A command relay served as a component on a starship, enabling the control of a drone freighter.
Back in 3 ABY, an Imperial convoy consisting of drone freighters was on its way to the Kuat Drive Yards, transporting hyperdrive components. When Rebel spies discovered the existence of this convoy, the Alliance launched a risky mission with the goal of seizing one of these freighters.
After infiltrating drone vessel 171, Chewbacca and Lando Calrissian needed to bypass the drone freighter's command relay. This was necessary to allow Wedge Antilles and Luke Skywalker to assume command of the ship's navigation and weapons. However, the access tube leading to the junction terminal was too small, forcing the Wookiee to forcibly remove the panel that covered it. With time running out to properly reprogram the command relay, Chewbacca resorted to manually overriding it by reconnecting two wires within the junction terminal. Having gained complete control of the freighter, the Rebels successfully captured drone vessel 171 and initiated their jump to lightspeed.