| 摘要 |
Provided is a programmable logic controller (1), comprising: a data collection unit (14) which, during the execution of a control program, collects I/O data passing between the system being controlled and the programmable logic controller (1); a collected data storage unit (11) which saves the I/O data which is collected with the data collection unit (14); a correct operation data storage unit (12) which stores as correct operation data, a designated portion of the input data saved in the collected data storage unit (11), which is I/O data during correct operations; a malfunction determination unit (17) which acquires I/O data from the collected data storage unit (11) and the correct operation data storage unit (12), compares for a given period the I/O data acquired from the collected data storage unit (11) with the I/O data during correct operations acquired from the correct operation data storage unit (12), and determines whether the control of the system is being correctly carried out; and a display control unit (18) which causes to be displayed in a programming tool (2) a determination result display screen which graphically displays the result of the determination from the malfunction determination unit (17). |
