Consists of:

• SEQUENCE_SWITCH1
• SEQUENCE_SWITCH2
• SEQUENCE_SWITCH3
• SEQUENCE_DOOR1

(This info was taken from TR Search Engine and was written by Michiel)
You must place the 3 sequence switches in the map (1 click above the floor) with the following ocb codes:
0 for SEQUENCE_SWITCH1
1 for SEQUENCE_SWITCH2
2 forSEQUENCE_SWITCH3
Below each switch must be a switch trigger for itself. No other triggers needed.
Place 6 SEQUENCE_DOOR1 objects in the map with ocb values of 0-5. Press the buttons 1-5 in the ocb window to activate the door. Place a trigger for the door behind it. This will close the door and reset the switches. Doors can only be opened once!
The game will open a SEQUENCE_DOOR1 when all 3 switches are pressed. The first time you must press them in the order 0-1-2. This will open door 0 and resets the switches. If the first combination pushed is not 0-1-2, door 2 will open. The switches only reset after triggering the door. If the combination 0-1-2 is not pressed and door 2 has already been opened, the switches will reset themself when lara presses another combination. After the combination 0-1-2 is pressed, all other doors can be opened by their combinations:
0-1-2 opens door 0
0-2-1 opens door 1
1-0-2 opens door 2
1-2-0 opens door 3
2-0-1 opens door 4
2-1-0 opens door 5
When door 1-5 is opened the switches will only reset if the door closes. Door 0 will reset the switches when it opens.

SEQUENCE_DOOR1
Used for the puzzle with the sequence_switches 1-3 (all six OCB’s are required).
0 – The first door that must be opened to make the others work
1 – Is usable once OCB = 0 is activated
2 – The “error door” – is opened with every wrong switch-combination until OCB = 0 is activated
3 – Is usable once OCB = 0 is activated
4 – Is usable once OCB = 0 is activated
5 – Is usable once OCB = 0 is activated