193
It is inevitable to meet exceptional conditions when the system is running so that PLC needs to be reset. Some specific variables in PLC need to remain the same value as the value before reset, making the system remain the state as before. The parameters of such variables are set as Persistence/Power Persistence.
CODESYS categorizes the parameters of Power Persistence: “Retain” and “Persistent”. It is for the system reset requirements of different levels.