Reliability and implementation of numerical control software based on EPP protocol

On the basis of the control system of EPP protocol of a parallel port on computer, which is hardly satisfied with the requirements of industrial environment on hardware, the purpose of compensating hardware with software is achieved on certain degree by optimizing the structure of programming and enhancing the fault-tolerant ability of the software. When the rapid forming system with the conception mentioned is used, the performance index would be still met with design requirements of the control system even if low cost control modules are used.