RFID reader integration with LogicMachine #

Task #

The example below shows how to integrate Idesco Access 7 C RFID reader over RS-232 port. The script below will read all RFID cards and log IDs. The script is easily adjustable if there is a necessity to trigger specific events.

Resident script #

Add the following resident script with sleep time set to 0.

if not port then
  require('serial')
  port = serial.open('/dev/RS232', {
    baudrate = 9600,
    parity = 'none',
    databits = 8,
    stopbits = 1,
    duplex = 'full'
  })

  function readid(port)
    local char, byte, line, id, csum, val
    cdOutChars = { 0x01, 0x02, 0x04, 0x07,
      0x08, 0x0B, 0x0D, 0x0E,
      0x10, 0x13, 0x15, 0x16,
      0x19, 0x1A, 0x1C, 0x1F
      }

    -- wait for start byte
    char = port:read(1, 1)
    if not char then
      return nil, 'timeout'
    end

    -- start byte must be Start character constant ‘B’

    if char ~= 'B' then
      return nil, 'wrong start byte'
    end

    -- read remaining line

    line = port:read(26,5)
    if not line then
      return nil, 'failed to read data'
    end
    csum = 0

    if line:sub(23, 23) ~= 'T' then
      return nil, 'End character constant T not found'
    end

    csum = 0

    for i = 1, 16 do
      val = tonumber(line:sub(i, i), 16)
      -- Incorporation of error in telegram for Testing LRC-checksum
      if math.random(1 ,16) > 15 then
      end
      csum = bit.bxor(csum, cdOutChars[val+1])
    end

    --// Add constants, 'B' at beginning + separation char '=' + 'T' in the end
    --lrc ^= 0x0B ^ 0x0A ^ 0x0A;

    csum = bit.bxor(csum, 0x0B)
    csum = bit.bxor(csum, 0x0A)
    csum = bit.bxor(csum, 0x0A)

    Tagtype = line:sub(22, 22)

    if Tagtype == '1' then
      --lrc ^= 1;
      csum = bit.bxor(csum, 1)
    end

    if Tagtype == '2' then
      --lrc ^= 2;
      csum = bit.bxor(csum, 2)
    end

    if Tagtype == '3' then
      --lrc ^= 3;
      csum = bit.bxor(csum, 3)
    end

    if Tagtype == '4' then
      --lrc ^= 4;
      csum = bit.bxor(csum, 4)
    end

    if Tagtype == '5' then
      --lrc ^= 5;
      csum = bit.bxor(csum, 5)
    end

    if Tagtype == '6' then
      --lrc ^= 6;
      csum = bit.bxor(csum, 6)
    end

    for i = 18, 22 do
      val = tonumber(line:sub(i, i), 16)
      csum = bit.bxor(csum, val)
    end

    csum = bit.rshift(csum, 1)

    -- verify checksum
    if csum ~= tonumber(line:sub(24, 24), 16) then
      return nil, 'invalid checksum'
    end

    -- return ID

    return line:sub(1, 16)
  end
end

id , errorstatus = readid(port)

if errorstatus ~= nil then
  if errorstatus ~= 'timeout' then
    log ('error status', errorstatus)
  else
  end

end

if id then
  log('RFID', id)
end