Abstract: Intelligent data storing apparatus for use in a control system comprising at least one programmable logic controller (PLC) for controlling one or more devices to perform a process, the process having a number of variants. The apparatus comprises means for receiving a data request including a code designating a process variant and a code indicative of one or more designated devices requiring control in order to implement the process variant; a database dictionary defining a tree structure relating operational data elements to particular variants of the process and particular devices; and means for retrieving operational data elements from the database using pathnames corresponding to the structure specified in the database dictionary and for formulating the retrieved data into a block having a predetermined structure for outputting to the PLC.