IWritePersistentData
- Namespace
- ZCore
- Extends
- Inherited Properties
- Inherited Methods
INTERFACE IWritePersistentData EXTENDS ZCore.IObject, ZCore.IError
CODESYS systems offer persistent variables that keep their values, after the PLC is stopped or even if the PLC crashes with an exception.
Persistent variables have to be declared in VAR PERSISTENT blocks. The controller must support this mechanism by means of a suitable memory (NVRam, UPS)!
Typically the VAR PERSISTENT variables are even stored there in a memory segment of their own.
This interface is used to offer consistent behavior of persistent variables throughout CODESYS platforms (e.g. TwinCAT.
Properties
BootDataLoaded
PROPERTY BootDataLoaded : BOOL
This property returns TRUE if persistent variables were loaded correctly when starting the PLC.
The property may return FALSE if no bootdata could be found on the system (typically when commissioning a machine) or
if bootdata was not compatible to the PLC due to changes in data structure etc.
Property Value
- BOOL
Methods
SavePersistentDataAsync
METHOD SavePersistentDataAsync ()
This method initiates saving of the persistent variables