Persistence as an option¶

Some function blocks in the CODESYS Building Automation library contain data which may require persistence. |OperationalTime|.tOp could be a good example. Of course, some applications may not require those values to be persistent, but rather save the resources needed to handle persistence. In case persistence is required, the CODESYS Application Composer Module “Persistence Manager” can be used to provide this. For detailed information about the “Persistence Manager”, see https://help.codesys.com/webapp/ac_pm_overview;product=core_Application_Composer.

Optional persistent aspects in the CODESYS Building Automation library carry the {attribute ‘ac_persist’} with a named “persistence group”. Right now, the CODESYS Building Automation library requires the application to use the “Persistence Manager” in a way to restore persistent aspects during initialization. To achieve this, set PersistenceManager.PersistenceChannel.xReadVarsDuringInit to TRUE.

Currently, the following “persistence groups” exist in the CODESYS Building Automation library:

• BuildingLib_OperationalTime - operational time / counters of actuators, aggregates, etc.