Most CAM systems generate one or more types of neutral language files containing instructions for a CNC machine. These are either in a binary format called CLDATA or some ASCII readable format tailored after the APT language.
APT is an acronym for “Automatically Programmed Tools,” software that accepts symbolic geometry and manufacturing instructions, and generates CLDATA describing the manufacturing operation in absolute terms. Some CAM systems provide a large degree of flexibility, allowing just about anything to be included in the neutral file, others are quite strict about what can and cannot be included.
At the other end of the equation sits the NC machine. It requires input customized for the controller being used and arguably to a lesser extent, the operator running the machine. Most important, the NC machine must be driven in a manner that satisfies shop floor criteria, which are primarily based on safety, efficiency, and tradition.
Between these two lies the post-processor. The post-processor is the software responsible for translating neutral instructions from the CAM system into the specific instructions required by the NC machine (Figure 1).
This software responds to the unique requirements and limitations of the CAM system, NC machine, and manufacturing environment. Therefore, post-processing is an important part of factory automation, as is anything that lies on the critical path between the design engineer and the shipping department.