An empirical study of applying a reflective-distributed memory for automation systems

摘要

Recently, utilizing ICT is a key of success in every field of industries, and its importance is growing more and more. Typical example is introducing ERP software which assists decision making of stakeholders by providing data regarding running business such as supply chain, procurement, inventory, finance, product lifecycle, projects, human resources, and so on in an integrated form. Especially for manufactures, vertical integration of data from a plant floor to the ERP is highly desirable. However, in most the case the vertical data integration is implemented via some relational database. Database has to endorse ACID property for its nature, and the ACID property could be a burden to realize the vertical integration in “real-time” manner. We propose a data management scheme that all the data at the plant floor, which are mostly held on PLCs' (Programmable Logic Controller) memory, are reflected to the memory which is held in some machine nodes of a data center. It allows users to see whole picture of the plant floor, and enables both data modification from both the data center and from the PLCs in a real-time manner from anywhere in the world. We describe the implementation of the proposing data management scheme and discuss what operations from the data center to the factory are applicable, against the relatively high communication latency from the plant floor to the data center.