From Halopedia, the Halo wiki
An actuator plug is an artificial intelligence-adjacent technology used by the Covenant and its various remnants, including the Banished. Due to the Covenant's religious doctrines, the empire restricted the use of volitional intelligences, and thus was unable to wield their power to the same extent as the United Nations Space Command. Actuator plugs serve to fill this void in the Covenant's industrial capacity, serving as semi-intelligent systems used to automate high-level tasks such as operating vehicle systems and heavy machinery.
Equipment known to make use of actuator plugs include the Shuku-pattern sentry turret, Bkowe'nei-pattern Vampire, and Banished automated turret. The Muz-pattern Wraith is fitted with twin medium plasma cannons, automatically operated by "dummy modules" - which are likely an alternate method of referring to actuator plugs.
Humanity have developed their own actuator plug technology. The RANGER-class Mjolnir armour set makes use of the 7P-LCF actuator plugs in its chest plate for managing the suit's energy shielding.
- Halo Waypoint, Canon Fodder - Didact's Delight (Retrieved on May 18, 2023) [archive]
- Halo Encyclopedia (2022 edition), page 301
- Halo: The Essential Visual Guide, page 200
- Halo Encyclopedia (2022 edition), page 274
- Halo 4: The Essential Visual Guide, page 162
- Halo 4, Armory: Ranger chest description (MCC) "Features 7P-LCF actuator plugs for its energy shield system."