Remanent data

The controllers have either a NOVRAM and/or a flash for saving remanent data.
The IN_OUT variables are monitored for changes in their values for automatic saving after a parameter change. In the event of a change, an internal variable in the library is triggered, with which the function blocks FB_HVACNOVRAMDataHandling or FB_HVACPersistentDataHandling are activated.

The IN_OUT variables are saved in a binary file in the flash if eDataSecurityType:= eHVACDataSecurityType_Persistent. The prerequisite for this is a single instancing of the function block FB_HVACPersistantDataHandling. Writing of the IN_OUT variables is deactivated if eDataSecurityType:= eHVACDataSecurityType_Idle.

Nevertheless, the variables must be located or addressed for remanent storage. They will then be saved in the NOVRAM in the event of a change of value. The prerequisite for this is the instancing of the function block FB_HVACNOVRAMDataHandling, as well as an instance of the respective data type that is to be saved.
Example: An instance of FB_HVACNOVRAM_Byte must be used in the case of a variable of type BYTE.

Notice

Flash destruction

An IN_OUT variable that has been declared as persistent must not be written cyclically if eDataSecurityType: = eHVACDataSecurityType_Persistent, since otherwise the flash will be prematurely destroyed. Regarding this subject, it is strongly recommended that you read the documentation on the function blocks FB_HVACNOVRAMDataHandling or FB_HVACPersistentDataHandling and familiarize yourself with the examples contained in the documentation!