| 摘要 |
PROBLEM TO BE SOLVED: To check that a program is accommodated to a change for operating PLC (Programmable Logic Controller) during operation and update it.SOLUTION: A compilation unit 12 compiles a source code 16 of any updated-version program and generates a machine language object 17 in conformity to constraint conditions, for example, "to retain an address of existing variables". When succeeding in compilation, the compilation unit generates unique identification information 18 corresponding to the machine language object 17 generated by an identification information generation unit 13 and the like and adds and registers it in a list. When the newest-version machine language object 17 is downloaded into a PLC 20, a programmable controller system acquires current identification information 23 of the PLC 20, determines whether or not the current identification information is registered in the list and permits the download, only when it is registered. |
