Appendix c crc-16 computation, Appendix c, Sentences. for definition of the crc, see – Vaisala WXT520 User Manual

Page 163: Appendix c, crc-16, Crc-16 computation

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Appendix C ______________________________________________________ CRC-16 Computation

VAISALA______________________________________________________________________ 161

APPENDIX C

CRC-16 COMPUTATION

The computation of the CRC is performed on the data response before
parity is added. All operations are assumed to be on 16 bit unsigned
integers. The least significant bit is on the right. Numbers preceded by
0x are in hexadecimal. All shifts shift in a zero. The algorithm is:

Initialize the CRC to zero. For each character beginning

with the address, up to but not including the carriage

return (<cr>), do as follows:

{

Set the CRC equal to the exclusive OR of the character

and itself

for count =1 to 8

{

if the least significant bit of the CRC is one

{

right shift the CRC one bit

set CRC equal to the exclusive OR of 0xA001 and

itself

}

else

{

right shift the CRC one bit

}

}

}

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