Wireless Modem

From ComputerCraft Wiki
Jump to: navigation, search
This page needs some serious TLC, stat!
Please help us by .
(Reason: The behaviour of Rednet has changed as of 1.5 - please consider updating this page with information. (Please don't add prerelease info!))
This page is for the Modem blocks. For the modem API, see Modem (API)
Grid workbench.png   Modem
Item ID ComputerCraft:CC-Peripheral
Damage Value 1
Peripheral? Yes- Modem (API)

Modems are blocks which can be used to wirelessly transfer data between Computers and Turtles, using the Rednet API or the Modem API. To place a modem on a side of a computer, right-click while sneaking.

It is also possible to turn the modem on and off by typing "rednet.open( side )" to open and "rednet.close( side )" to close.

Modems can send messages to other modems located up to 64 meters away, or 16 meters during a thunderstorm. As of 1.4 Modem range is increased with higher altitudes. If there is no thunderstorm, the range will always be higher than 64, and at max altitude you would have a range of 384 meters.

In 1.4 and 1.41 there is a miscalculation that causes the range to only be 381 meters at max altitude.

As of the 1.5 update for ComputerCraft, Wireless Modems can send messages on specific channels.

See also: Wired Modem, Ender Modem.


Grid stone.png
Grid stone.png
Grid stone.png
Grid stone.png
Grid ender pearl.png
Grid stone.png
Grid Modem.png
Grid stone.png
Grid stone.png
Grid stone.png

Example (Modem API)

  • Place 2 computers and add modems to them by clicking the right mouse button while sneaking.
  • Access them, and start Lua.
  • Once Lua has started, wrap your modem using peripheral.wrap() (something like "modem = peripheral.wrap("<side of modem>")
  • Type "modem.open (<A modem port number, anything from 1 to 65535>)" on one computer.
  • Check if there exists a connection: a dim, red light should be found on the modem.
  • Now, type "modem.transmit (<Same number as above>, <Also the same number>, 'Your message')" on the other computer. This should send your message to all computers connected.
  • Opening the first computer should show the message written on the second computer.

Modem as a Peripheral

To use a Modem as a peripheral, you need to either call a method directly using peripheral.call(), or, wrap the modem using the Peripheral API. Wrapped modems provide all functions listed in the Modem API.

For this example, we have a Modem connected to the top of our Computer, we are going to open channel 5:

-- Immediately invoke a method without wrapping
peripheral.call( "top", "open", 5 )
-- You can also "wrap" the peripheral side to a variable:
local modem = peripheral.wrap( "top" )
modem.open( 5 )


1.3Added Wireless Modems.
1.4The send and receive range of wireless modems now increases with altitude, allowing long range networking from high-altitude Computers.
1.5Redesigned Wireless Modems; they can now send and receive on multiple channels, independent of the computer ID.
1.51Changed crafting recipe.
Grid Redstone.pngComputerCraft Blocks and Items
Grid paper.png  Blocks
 Iso Computer.png  Computer Iso Advanced Computer.png  Advanced Computer Iso Command Computer.png  Command Computer Iso DiskDrive.png  Disk Drive
 Iso Monitor.png  Monitor Iso Advanced Monitor.png  Advanced Monitor Iso Printer.png  Printer Grid turtle.png  Turtle
 Grid Modem.png  Wireless Modem Grid Ender Modem.png  Ender Modem Grid Wired Modem.png  Wired Modem Grid Networking Cable.png  Networking Cable
Grid paper.png  Items
 Grid Pocket Computer.png  Pocket Computer Grid Advanced Pocket Computer.png  Advanced Pocket Computer Grid disk.png  Floppy Disk Grid printed page.png  Printed Page
 Grid printed pages.png  Printed Pages Grid printed book .png  Printed Book