| 摘要 |
A PLC monitoring system of an embodiment is provided with: a programmable logic controller (3) comprising an arithmetic processing unit (6) which performs determination processing in response to an instruction from a user, an internal device (5) which the arithmetic processing unit (6) uses, and a control unit; a display unit (1) which connects with the programmable logic controller (3) and displays device data relating to the internal device (5); and a storage unit which holds the device data, and the control unit determines whether or not the display unit (1) can acquire the device data, and when the display unit (1) cannot acquire the device data, causes the storage unit to hold interruption period device data that is the device data during an interruption period from when the display unit became unable to acquire the device data until when the display device becomes able to acquire the device data again. |
