Control method in safety control system and safety control system

摘要

To provide a safety control system capable of ensuring the security of an operation command given from an external device.SOLUTION: The safety control system that realizes functional safety according to an example of the present disclosure includes: an arithmetic processing unit that executes a safety program; and an access management unit that updates held variables in response to an access from an external device. The arithmetic processing unit starts executing the safety program when a specific variable is updated to a predetermined value by the access management unit. The access management unit receives a command for updating variables by secure communication with the external device.SELECTED DRAWING: Figure 1