Calculate Generic CRC

#Firmware/v292

v = crc.calc(init, polyrev, xor, txt)

Calculate a general purpose CRC (up to CRC-32).

Parameter Type Description
init integer Initial value
polyrev integer The polynomial value, reversed. Use negative values when the input and output are reflected.
xor integer The value to XOR at the end
txt string The text to CRC

Examples:

  • CRC-32:
    • crc.calc(0xffffffff, -0xedb88320, 0xffffffff, txt)
  • CRC-16/Modbus:
    • crc.calc(0xffff, -0xa001, 0, txt)
  • CRC-16:
    • crc.calc(0xffff, 0x8408, 0, txt)
  • CRC-16/Xmodem:
    • crc.calc(0, 0x8408, 0, txt)
  • CRC-16/DNP:
    • crc.calc(0, -0xa6bc, 0xffff, txt)