| 摘要 |
PURPOSE:To promptly shift to a control program before change when a fault by the change of the control program is generated in a controller with a built-in control program. CONSTITUTION:At the time of storing a new control program read from an FD drive 70 in an HDD 30, an old control program is copied in a program area 33 and the operation contents are recorded in a maintenance history 31. Also, when the fault is generated in the stored new control program, an SVP 10 refers to the maintenance history area 31, selects the control program for not generating the fault from the program area 33, performs a processing for shifting to the control program and records the operation contents in the maintenance history area 31. Thus, the shifting operation of the control program is simplified, operation errors are reduced and the maintenance time is shortened. |
