The Ark has several supraluminal communication towers with the purpose of transmitting data to and from the weapon installations that make up the Halo Array.
Each Halo has a designated Control Room which activates the Halo's weapon systems upon receiving the data, as well as emergency shutdown protocols to disable the systems and halt the Halo's activation.
Like the Cartographer, these Control Rooms are often protected by a large energy barrier and patrolled by high security Sentinels to protect from misuse. The Control Room is integral to the maintenance of the Halo's weapon systems, and the interior leads deep down to the Halo's superstructure in a maze of winding tunnels and shifting walls.