Covers

Covers are items that can be placed on the sides of machines, cables, wires, and pipes to adjust their behavior or transmit internal information. Interact with covers in the following ways.

• Sneak right-click with a cover in hand to place it on a valid block.
• Sneak right-click with an empty hand to adjust a cover's settings, or go through the machine's GUI.
• Right-click with a screwdriver to iterate through a cover's settings.
• Right-click with a soldering iron to change the redstone signal strength. Strong signals can transmit through blocks while a weak signal cannot.
• Right-click with a crowbar to remove a cover.
• Sneak right-click with a Cover Copy/Paste Tool to copy a cover's settings. Right-click to paste on a cover of the same type.

Multiple covers can exist on the same block and may even work together to accomplish a task. For example, a fluid detector cover can pass a redstone signal to a machine controller cover to disable a fluid regulator. If multiple covers on the same block update within the same game tick, they are updated in the order of the side index: Down, Up, North, South, West, East.^[1]

The categories below are all the available covers in GTNH. Many of these also have wireless versions which operate in the exact same manner except they also emit redstone signals on a specific wireless frequency/channel.

• Conveyor Module - Imports or exports N items every few ticks. The speed scales with the voltage tier.
• Robot Arm - Imports or exports N items every few ticks to/from specific slot numbers. The speed scales with the voltage tier.
• Filtered Conveyor (Import) - Imports 64 items per tick with an optional filter (drag from NEI). Imports anything while no filter is set.
• Filtered Conveyor (Export) - Exports 64 items per tick with an optional filter (drag from NEI). Exports anything while no filter is set.
• Item Detector - Emits a redstone signal if the number of items is greater than or equal to a specific threshold. Look at the entire inventory or a specific slot number.
• Item Holder - Provides a few extra inventory slots for quick access. Very useful for molds, lenses, fluid cells, etc.
• Shutter Module - Controls the flow of items (and fluids). Typically used with a machine controller cover.

• 
  Conveyor Module
• 
  Robot Arm
• 
  Filtered Conveyor (Import)
• 
  Filtered Conveyor (Export)
• 
  Item Detector
• 
  Item Holder
• 
  Shutter Module

• Pump - Imports or exports N liters every few ticks. The speed scales with the voltage tier.
• Fluid Regulator - Imports or exports N liters every few ticks with additional control over the flow rate. The speed scales with the voltage tier.
• Steam Valve - Imports or exports N liters of STEAM every few ticks with much higher throughput. The speed scales with the voltage tier.
• Overflow Valve - Voids excess fluids once over a certain threshold. The threshold scales with the voltage tier.
• Ender Fluid Link - Imports or exports up to 8,000 liters per tick to/from other ender fluid links on the same channel, similar to ender tanks.
• Fluid Filter - Control the flow of fluids with an optional filter. Imports or exports anything while no filter is set.
• Fluid Detector - Emits a redstone signal based on the fill level of the tank (empty=0, full=15) once above a certain threshold.
• Fluid Storage Monitor - Displays the current fill level of a tank (purely visual). No function otherwise.
• Shutter Module - Controls the flow of fluids (and items). Typically used with a machine controller cover.
• Drain Module - Collects rain and any other fluids directly in front of it. Protects against the rain too.

• 
  Pump
• 
  Fluid Regulator
• 
  Steam Valve
• 
  Overflow Valve
• 
  Ender Fluid Link
• 
  Fluid Filter
• 
  Fluid Detector
• 
  Fluid Storage Monitor
• 
  Shutter Module
• 
  Drain Module

• Energy Detector - Emits a redstone signal based on the fill level of the battery (empty=0, full=15) once above a certain threshold.
• Solar Panel - Powers a machine if facing UP. Only 1/8 as effective during night/rain, but the sun can be obstructed without issue. Needs to be cleaned every so often by right-clicking with an empty hand and a water bucket in your inventory. The power scales with the voltage tier. Can function under glass / transparent blocks and while cable mounted.
• Wireless Energy - Powers a machine from a wireless EU network. The power scales with the voltage tier.
• Tesla Coil - Allows a machine to receive power from a nearby Tesla Tower. The rich edition just makes extra noise.
• Power Pass - Carries power through to adjacent machines. Avoids having to run a cable along many at once.

• 
  Energy Detector
• 
  Solar Panel
• 
  Wireless Energy
• 
  Tesla Coil
• 
  Power Pass

• Activity Detector - Emits a redstone signal based on recipe progress (start=0, end=15). Also can detect when a machine is idle.
• Player Detector - Emits a redstone signal when a player is within 10 blocks.
• Metrics Transmitter - Generates a sensor card from a GregTech machine for use in information panels. Works across dimensions.
• Machine Controller - Enables/disables machines and covers with a redstone signal. If safe mode is enabled and the machine runs out of power, the cover automatically switches to "disable machine" mode, forcing the machine offline until the player switches it back.
• Wireless Machine Controller - Enables/disables machines and covers with a redstone signal from an advanced wireless transmitter.
• Needs Maintenance - Emits a redstone signal when a multiblock has X number of maintenance issues.
• Redstone Transmitter - Emits a redstone signal on a specific wireless frequency. The advanced version can also invert the signal.
  • Internal - The redstone signal comes from covers on the same block.
  • External - The redstone signal comes from other blocks, such as a red alloy wire.
• Redstone Receiver - Receives a redstone signal on a specific wireless frequency. The advanced version has optional logic gates.
  • Internal - See wireless machine controller (renamed in 2.9).
  • External - The redstone signal is passed to an adjacent block, such as a red alloy wire.

• 
  Activity Detector
• 
  Player Detector
• 
  Metrics Transmitter
• 
  Machine Controller
• 
  Wireless Machine Controller
• 
  Needs Maintenance
• 
  Redstone Transmitter
• 
  Redstone Receiver

• Crafting Table - Adds an easily-accessible 3x3 crafting grid.
• Computer Monitor - Displays an animated computer screen (purely visual). No function otherwise.
• Heat Vent - Cools hot coolant back into IC2 coolant. Works on anything with an input or output fluid tank. Better heat vents are faster.
• Plates/Planks/Foils - Blocks specific types of inputs, outputs, and rain. Switch the allowed types by right-clicking with a screwdriver. Paper also works.
• Lens - Displays a colored lens (purely visual). No function otherwise.

• 
  Crafting Table
• 
  Computer Monitor
• 
  Heat Vent
• 
  Plank
• 
  Lens