os-rfidreader.md

os_rfidreader

Summary

The os_rfidreader component scans nearby RFID-bearing targets and reports them through both return tables and rfidData signals. OpenSecurity exposes this component in two forms:

• a placed RFID reader block
• an RFID reader card upgrade

Both surfaces use the same component name and nearly the same callback behavior.

Availability

• Repository: opensecurity
• Component name: os_rfidreader
• Typical hosts:
  • placed OpenSecurity RFID reader block
  • OpenSecurity RFID reader card inside supported devices such as tablets

Usage

local component = require("component")
local reader = component.os_rfidreader

if not reader then
  error("os_rfidreader component not installed")
end

What Gets Detected

The scan logic looks for RFID data in three places:

• RFID cards in player inventories
• RFID cards in OpenComputers drone inventories
• entity NBT data under entityData.rfidData

Each found RFID payload sends:

computer.signal("rfidData", name, range, data, uuid)

Signal fields:

• name: player display name, drone/entity name, or other entity command sender name
• range: distance from the host device
• data: RFID payload string
• uuid:
  • real UUID normally
  • "-1" when ignoreUUIDs is enabled

The returned scan table also includes:

• locked:boolean

Range And Energy

• Requested range is clamped to OpenSecurity.rfidRange.
• The configured default max is 16, and the config allows 1 through 64.
• After clamping, the implementation divides the range by 2.
• Energy cost is 5 * effectiveRadius.

Block versus card difference:

• The placed block returns false, "Not enough power in OC Network." on low power.
• The card driver throws an exception with the same message.

API

greet

• Syntax: reader.greet()
• Returns: string
• Purpose: Returns the built-in OpenSecurity greeting.

scan

• Syntax: reader.scan([range])
• Returns:
  • Success: table
  • Failure:
    • block reader: false, reason
    • card reader: exception
• Purpose: Scans the surrounding area for RFID payloads.

Parameters:

• range:number optional: requested radius before clamping and halving.

Returned table entry format:

• entry.name
• entry.range
• entry.data
• entry.uuid
• entry.locked

Behavior:

• One returned table entry is created for each RFID payload found.
• A single player or drone can contribute multiple entries if carrying multiple RFID cards.
• An empty table is returned when nothing is found.

Example:

local results, reason = reader.scan(16)
if results == false then
  error(reason)
end

for _, entry in pairs(results) do
  print(entry.name, entry.data, entry.uuid, entry.locked)
end

Example

local event = require("event")

local results = reader.scan(16)
if results == false then
  error("scan failed")
end

for _, entry in pairs(results) do
  print("Found RFID:", entry.name, entry.data)
end

while true do
  local _, _, _, eventName, name, range, data, uuid = event.pull("computer.signal")
  if eventName == "rfidData" then
    print(name, range, data, uuid)
  end
end

Related

• component
• os_magreader
• os_cardwriter