| 摘要 |
PURPOSE:To discriminate ineffective and effective record length in a record unit, by taking the logical record length as one unit and adding a horizontal parity check (LRC) byte. CONSTITUTION:When records A and B are collected in mixture, CPU11 generates a horizontal parity check (LRC) byte based on the record length and stores it to a memory 12. Even if an error is detected at an A1 record, a B1 record checks the LRC byte of the 2nd block and if it is normal, the B1 record is made effective. Inversely, if the record B1 of the 1st block has an error, when the A1 record before it is normal, the LRC byte of the B1 record is checked and only the B1 record is made ineffective. |
