Each record ends with a CHKSUM field that contains the ASCII hexadecimal representation of the two’s complement of the 8-bit bytes that result from converting each pair of ASCII hexadecimal digits to one byte of binary, from and including the RECLEN field to and including the last byte of the INFO/DATA field. Therefore, the sum of all the ASCII pairs in a record after converting to binary, form the RECLEN field to and including the CHKSUM field, is zero.