| 摘要 |
PROBLEM TO BE SOLVED: To provide a PLC which can automatically download an objective program when the PLC is replaced. SOLUTION: In the PLC with a function automatically program-transferable through a network, a PLC 1 and a engineering devices 2 are provided. The PLC has following functions. the PLC status function 3, at exchange of PLC, the status showing initializing state is, at first, switched on besides a normal function 5, when a program is downloaded in PLC, the status is switched off. a network function 4 the engineering device 2 has following functions: a current program 10 is holding the newest program as an automatic program transfer mean program database 9 network function 12 PLC status monitoring function 8 automatic download function 6 which automatically download data of an objective current program to the PLC confirming its initialization status. When the status showing PLC initialization state changes into on state, the PLC status monitoring function detects it, then the objective program is automatically downloaded to PLC by the automatic program download function.
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