| 摘要 |
PURPOSE:To attain ease of reverse sequence operation of a process by storing the execution order of a forward operating instruction. CONSTITUTION:The forward operating instruction is executed at the step 1 and also ''1'' is stored in a forward operating execution sequence recording table. The forward operating instruction 2 is executed at the step 2 and ''2'' is stored in the forward operating execution sequence recording table. The operating condition is discriminated by a discrimination instruction 1 at the step 3, resulting that the step is bypassed at the step 4 and enters the next step 5, the forward operation instruction 4 is executed and ''4'' is stored in the forward operating execution sequence recording table. The similar operation is conducted till the step 8. If any error takes place in this state, since the step numbers are stored as 6, 5, 4, 2, 1 in the reverse order in the forward operating execution recording table, the corresponding instruction is selected from a reverse operating instruction table corresponding one to one to the forward operation in the sequence above and the sequence is executed in the reverse order. |
