| 摘要 |
An execution code of a user program applicable to a PLC is fitted and arranged to an adequate block among memory blocks of variable sizes, and execution order and position information of each execution code are downloaded to the PLC along with recorded execution table. A CPU module of PLC sequentially executes each execution code randomly arranged on a memory with reference to the execution table. Because an execution code is loaded on a memory block having respectively different sizes such as N, 2N and 4N, utilization of non-use space can be improved over a conventional allocation method of fixed size. An execution table is utilized to discontinuously configure a program execution area, whereby a user program can be easily modified or added during PLC operation. |
