Controlling doors, gates and airlock doors

In Stationeers a door is more than a hole in the wall. It withstands a certain pressure difference, needs power and can be opened and locked through logic. Knowing this, you build airlocks that never open both sides at once by accident.

The main doors compared#

Door	Power	holds a pressure difference of	Kit
Composite Door	10 W	300 kPa	Kit (Door)
Glass Door	10 W	200 kPa	Kit (Door)
Manual Hatch	10 W	500 kPa	Kit (Door)
Airlock	25 W	1000 kPa	Kit (Airlock)
Blast Door	25 W	no limit, does not break from pressure	Kit (Blast Door)

The Kit (Door) from the Autolathe builds a glass door, composite door, composite roll cover, hatch or floor hatch, as you choose. According to the game data the Kit (Airlock) comes from the Hydraulic Pipe Bender. The kit for the large Blast Door needs the second printer tier, and the door itself takes six steel sheets.

Building in three steps#

Composite and glass doors go up in three stages: place the kit, then insert a plastic sheet with the welding torch, finally the glass with the crowbar. The glass door takes two glass sheets, the composite door one. Deconstruction runs in reverse, with angle grinder, hand drill and finally the wrench.

On these doors power and data have separate ports. They sit at the bottom of the door. The cable must lead right up to the door plane, otherwise it finds no port.

Pressure: what a door can take#

Every door and every wall has a limit for the pressure difference between its two sides. From 80 % of that limit the part counts as stressed.

A worked example on the Moon, with vacuum outside:

• 101 kPa inside against 0 kPa: the glass door carries 101 of 200 kPa, about 51 %. No problem.
• You pump the room up to 170 kPa: that is 85 % – the door is stressed.
• A safe upper limit for parts rated 200 kPa is 150 kPa against vacuum, which is 75 %.

If you want to run a room at high pressure, use the Airlock with 1000 kPa or build reinforced walls. More about walls is in Building: frames, walls, windows, floors, grid.

The blast door is a special case: no limit is set for it, and the game's pressure damage calculation skips parts without a limit. So pressure does not damage it. But it does not check pressure when opening either – opened against vacuum, the air escapes.

A door's logic values#

Composite door, glass door, airlock and blast door share the same values:

LogicType	read/write	meaning
Open	rw	1 = open, 0 = closed
Lock	rw	1 = locked, can no longer be operated by hand; logic still works
Mode	rw	what a click does: 0 Operate opens and closes, 1 Logic only reports a request
On	rw	on/off
Setting	rw	in Logic mode the request: 1 = please open, 0 = please close
Idle	r	1 = door stands still, 0 = door is moving
Power, RequiredPower	r	power values

To open and close you write Open, to lock you write Lock. Important: somebody can also open a door by hand. So read Open back before you decide – do not write blindly.

Logic mode is meant for doors guarded by a chip. A click then does not move the door but sets Setting to 1 when it is closed and to 0 when it is open. Your program reads this request and decides whether to write Open – for example only when the other airlock door is shut. When the chip opens or closes the door, Setting follows Open again. With Idle you wait until a door is really shut instead of sleeping for a fixed time.

For consoles there are ready-made circuit boards: Door Control, Airlock and the advanced airlock. The airlock board links two doors, vents and gas sensors and pumps the chamber empty by itself, down to 0.005 kPa at most, and full again, up to about 100.3 kPa. A chip gives you more control.

Program: airlock with interlock#

An airlock has an inner and an outer door. Both must never be open at the same time. The program locks the other door while one is open. If both do end up open, it closes the outer one. If a door is missing from the network, both are closed and locked.

# Airlock: never both doors open at once
define DOOR -2105052344        # Airlock (StructureAirlock)
define NINNER HASH("Airlock Inner")   # name of the inner door
define NOUTER HASH("Airlock Outer")   # name of the outer door
alias inner r0
alias outer r1
alias both r2
alias lock r3

start:
yield
lbn inner DOOR NINNER Open 0
bnan inner emergency
lbn outer DOOR NOUTER Open 0
bnan outer emergency
mul both inner outer           # both open?
beqz both interlock
sbn DOOR NOUTER Open 0         # then close the outer one

interlock:
sgtz lock inner                # inner open: lock outer
sbn DOOR NOUTER Lock lock
sgtz lock outer                # outer open: lock inner
sbn DOOR NINNER Lock lock
j start

emergency:
sbn DOOR NINNER Open 0         # a door is missing: close all
sbn DOOR NOUTER Open 0
sbn DOOR NINNER Lock 1
sbn DOOR NOUTER Lock 1
j start

How it works:

1. Both lbn read the state with batch mode 0. If a door is missing, lbn returns NaN and bnan jumps into the emergency branch.
2. mul only gives something other than 0 when both doors are open.
3. sgtz turns “open” into a 1 for the other door's Lock. Once the door is closed, the other one is released again.

What “safe” means depends on the place. For an airlock to vacuum, “closed and locked” is right. For a storage door inside the base, “free” would be the better choice – otherwise a network fault locks you out. Keep in mind: not even the crowbar opens a locked door without power.

Power for this example: two airlock doors at 25 W each plus the IC housing at 50 W make 100 W.

The program does not control the pressure in the chamber – for that you also need a vent and a sensor. The academy builds the whole airlock step by step.

Typical mistakes#

• The door ignores Open: does it have power? Is the cable plugged in at the bottom edge of the door? Is it on the same data network as the chip? Lock is not to blame here – it only blocks the hand.
• The door does not open when clicked although it has power: it is in Logic mode (1). A click then only reports a request in Setting.
• The chip locks both doors open: without the “both open” check they lock each other in the open position.
• All doors open at once: both doors share one name. Inner and outer need their own names.
• The door counts as stressed: the pressure difference is above 80 % of its limit. Lower the pressure or build a stronger door.

Next steps#

• Building an airlock: layout, control, common mistakes – layout, control and common mistakes of an airlock
• Building: frames, walls, windows, floors, grid – frames, walls and their pressure limits
• Sensors: gas, daylight, motion, occupancy – measuring the pressure in the chamber
• IC10: control a device by name – devices by name and batch mode
• Academy: doors and locks, interlock, airlock basics, airlock sequence