Secondary Defense System


Defense system/weapon
Prevent spread of humans throughout the subnet

The secondary defense system (aka secondary DS, SDS, SDS-TC) is part of the subnet's defense system.


The SDS's primary purpose is to control a turret chain made up of at least 512 turrets (hence SDS-TC). The turrets are designed to keep out intruders from accessing the Core. The human recognition data contained by the primary defense protocol 1-12 would most likely have been used to determine if the attacker was a human or a sub-bot for example.

A secondary purpose of the SDS is to prevent human hack attempts and, in general, stop humans/foreign threats from entering the Edge.

Turret terminalsEdit

Turret access map

A map of the Turret terminal.

Turrets have their own terminals, in which there is a blueprint of the turret. There are also two "switches", one to arm/disarm a turret and one to put a turret online/offline. Neither can be accessed while secondary defense system protocols are down.

The player can't shut down an armed turret. There is a bleak signal light in the control room to point out if the turret is online or not without having to use a connection pod. The right light signals that the turret is offline and similarly the left light signals it to be online.

If a turret gets offline, it must be turned online, either manually through its turret terminal (see below) or through secondary defense system protocol 2-17 or 2-18. 2-17 scans through the chain and finds out which turret is offline and turns it on. 2-18 on the other hand, automatically resets the chain and is inaccessible if the turret chain is stable. Presumably a sub-bot is sent to deal with the damage if the protocol is unable to proceed. Using the programs doesn't arm the turret, and it appears that this is a job that has to be done manually via turret terminal.

If secondary defense system protocol is offline, it can't turn a turret on and the whole chain is offline.

There is only one known turret, numbered 512.

A summary of the turret protocols:

  • 2-17 - Turret chain check. If a turret is offline it resets the chain.
  • 2-18 - Turret chain reset.
  • There also seems to be a protocol that open the electrical gate if the SDS goes down.

Human hack attemptsEdit

Protocols for human hack attempts are controlled behind the gate 3/18. They are activated upon hack attempts and work as sort of a firewall.

  • 54-1 - safety switch that is meant to trigger an alert if the next three protocols are manipulated
  • 54-2 - controls filtering of any messages from outside the defense system.
  • 54-3 - controls access to elevator graphs.
  • 54-4 - controls access to Subnet Infestation Map.

Human hack attempts are also blocked by a series of gates and switches that control doors in the defense system corridors that must be activated/deactivated in a specific order for progress to be made. This would presumabley allow extra time for sub-bots to be alerted to and respond to a threat.


“turret chain stable”
— Secondary defense system protocol 2-17

“turret 512 offline”
“turret chain broken”
“/turret reset required”
— DS

See alsoEdit

Submachine 6 Locations
Lobby - Cliffs - Tunnels - Chronon - Defense system entrance - Defense system corridors - Mainframe