| 摘要 |
PURPOSE:To ensure a highly accurate control function with a simple constitution, by deciding the presence or absence of a desired index on the basis of the fetched maximum index. CONSTITUTION:When a TNO(track number) changing point detecting signal is produced, a latch circuit 320 latches a data y' from a present data generating circuit 318 via a bus 321 for index and stores the data to a maximum index storing circuit 322 in a control circuit 201 via a maximum index storage input circuit 323. Then a flip-flop circuit 316 is reset. That is, the maximum index data is stored for a TNO to be searched. Therefore it is easily decided for propriety for searching of the desired index. Then an error display device 114 is turned off to show an index search enable state, then turned off to show an index search unable state respectively. |
