The STEP-NC AP238 standard is the result of international effort to replace the RS274D (ISO 6983) M and G-code stan- dard with a modern associative language that connects the CAD design data used to determine the machining require- ments for an operation with the CAM process data that solves those requirements. The STEP-NC is a modern, asso- ciative communications protocol that connects computer numerically controlled (CNC) process data to a product description of the part being machined. Integration of the CNC model into STEP to produce ISO 10303-238 was done in the United States, under the NIST ATP Model Driven Intelligent Control of Manufacturing project, led by STEP Tools, Inc. (‘As of 20 July 2016, the STEP Tools listed on its website, www.steptools.com’) with an industrial review board (IRB) consisting of companies, CAD and CAM software devel- opers, machine tool manufacturers, job shops and industry experts (Hardwick et al. 2013). The new programming method that uses standards ISO 14649 and ISO 10303-238, known as STEP-NC, is increasingly applied in the field of CNC machine tool programming, as an Methodology for machining robot programming based on STEP: NC is described by using the IDEFO diagram (Sddski, Salonen, anc Paro 2005; Zhang et al. 2012; Zivanovic and Glavonjic 2014). The IDEFO is used to describe a programming method as a structurec representation of the activities within the considered program: ming methodology. This methodology is a structural representa: tion of activity, which can be viewed at several different levels where each level consists of a set of hierarchical diagrams with This paper considers an Indirect programming method, based on standard ISO 10303-238, using the developed ‘igure 2. STEP-NC digital thread manufacturing data chain. Figure 4. Top-level IDEFO diagram for an indirect programming method of robot machining tasks based on STEP-NC. Top level child diagram AO describes a basic flow of activ- ities and it is illustrated in Figure 5. According to the IDEFO methodology, by analysing diagram AO, one gets the basic flow of activities: Al: Generating of STEP files and toolpath in A single function represented in the top-level context dia- gram may be decomposed into its major sub-functions by creating its child diagrams. Each child diagram contains the Figure 3. Indirect STEP-NC programming. Figure 5. An indirect programming method of robot machining tasks based on STEP-NC . STEP-NC Machine - New Project Figure 6. Import options of STEP-NC machine software. Figure 7. Robot language converter (RLC). Figure 8. STEP and *.XML representation of Mitsubishi Movemaster EX robot for machining simulation in STEP-NC machine environment. Figure 11. Comparative review of parts of the programmes. (a) P21 format. (b) Generated interfile. (c) Programme in robot language Figure 12. Toolpath simulation of generated robot language. Figure 13. Robot machining simulation of the first and second example based on STEP-NC programme. Figure 14. The first example.
