v50 Steam/Premium information for editors
  • v50 information can now be added to pages in the main namespace. v0.47 information can still be found in the DF2014 namespace. See here for more details on the new versioning policy.
  • Use this page to report any issues related to the migration.
This notice may be cached—the current version can be found here.

40d:Pressure plate

From Dwarf Fortress Wiki
Revision as of 04:35, 2 April 2009 by Moleculor (talk | contribs) (→‎Closing a floodgate when submerged: Clarification about whether you actually need to push the o key by default. You don't.)
Jump to navigation Jump to search

Pressure plates work somewhat like levers, but instead of being actively toggled, they're activated by the weight of something on them.

Pressure plates are not configured during use, but upon placement. While placing a pressure plate, you can configure it to trigger when the following things are on it:

  • Water/Magma - choose minimum and maximum levels
  • Creatures - choose minimum and maximum size; creatures of the size selected will be listed as example. You can pick whether your own citizens will trigger the plate or not.

Pressure plates default to toggleable, where they send an On signal when the determined weight is upon them and send an Off signal when it's released. Pressing o will change them to one-use mode, where upon being activated, they do their work then deconstruct themselves, ceasing to operate altogether.

Pressure plates can be linked to all the same objects levers can. The effects are listed in the Lever page.

A toggleable trap may prove useless when there is a large amount of invaders walking back and forth over it, as there will not be enough time for it to activate before it is switched again. Berserk dwarves will set off pressure plates.

Permanent Effect Pressure Plate System

It is possible to hook a toggleable pressure plate up to a device which makes its effect permanent until a lever is flipped. One way to do that is to build a water-sensing pressure plate in a 1x1 room, link that to your trap (a drawbridge, for example), build a hatch above it, link the hatch to the original pressure plate outside, and then put water on the hatch. When an enemy steps on the pressure plate, the hatch opens, the water falls onto the other pressure plate (water-sensing pressure plate), and it raises the drawbridge.

To make it resettable, you can use pumps controlled by a lever or by dwarf-power to move the water back to where it started. You can also build a flood-gate next to the water-sensing pressure plate (linked to a trigger obviously) and have the water flow and spread-out into a room where it can evaporate, however, water in a 1x1 tile will not require a lot of room to evaporate.

You can use this pressure plate system as an inverted trigger system. In otherwords, a lever that controls the permanent-effect pressure plate system can be flipped from off to on and subsequently trigger a trap or mechanism from on to off as a result, and vice versa. It depends on the water level settings used for the water-sensing pressure plate:

  • 3 to 7 - Normal, on is on and off is off
  • 0 to 2 - Inverted, subsequent state is opposite the main trigger

The water-sensing pressure plate can be set to trigger for water levels 0 to 2 or 3 to 7 because if the room above is filled to the brim with water, then the 1x1 room will fill-up to level 7 quickly and when opening the floodgate or pumping it out will drop to level 2 or below quickly.

Shortcut b-T-p
Components used: Mechanism

Common procedures

Closing a floodgate when submerged

For this example, say we want to close a floodgate when a reservoir reaches a depth of 5.

  • Build the pressure plate, set to activate under water (w) from 0 (a, s) to 4 (z, x). Make sure it is set to reset (o) (The default is auto-reset and does not need to be changedv0.28.181.40d, you'll know it's set because the screen will read 'Resets').
  • Place the floodgate
  • Connect a lever to the floodgate, and open it.
  • Optionally remove the lever.
  • Connect the pressure plate to the floodgate.
  • Allow the pressure plate to be submerged.

The floodgate should close a few seconds after the water reaches a depth of 5 or more, and open again when the depth falls to 4 or less.

It's worth noting that the reaction time of the pressure plate-floodgate system is quite large - the reservoir may overflow before the floodgate shuts. In order to prevent this (for example, when building a well filled from a river or brook), build a large run-off pool. This allows the gate enough time to close, and the water will instead continue to spread out instead of overflowing, as it would have in a smaller pool.


Rooms
Furniture
Animal trapAnvilArmor standBedBinBucketCabinetCageCoffinContainerRestraintSeatStatueTableWeapon rack

Access
DoorFloodgateBarsGrateFloor hatchBridgeRoadWindow
Constructions
Machine & Trap parts
Other Buildings
Related Articles