Raw data is further processed (e.g. data cleansing, signal conditioning, aggregation) and used by the control system (e.g. control loops). Decisions are taken by the control system and set points are changed based on the raw data.

How the raw data is used by the control system significantly impacts the production outcome in terms of quality and throughput. Exposing how the control system uses the raw data is thus meaningful.

By identifying a Programming model ([3], §4.3) consisting of programs, tasks, function blocks, input variables, output variables, input/output variables, complex processing of raw data can be mapped to OPC UA constructs and exposed. To this end, the OPC Foundation has released the OPC 30000 - UA Companion Specification for IEC61131-3 Model 1.02.

All the input variables, output variables, and input/output variables of the input, intermediate and output function blocks are also exposed.