 It is computed by summing the decoded byte values and extracting the LSB of the sum (i.e., the data checksum), and then calculating the two's complement of the LSB (e.g., by inverting its bits and adding one).For example, in the case of the record , the sum of the decoded byte values is + + + + + + = codice_1, which has LSB value codice_1.The two's complement of codice_1 is , which is the checksum byte appearing at the end of the record.