The open architecture computer numerical control (OACNC) system meets the individualized demand of modern industry for its characteristics of flexibility, adaptability, versatility, and expansibility. Existing OACNC systems depend on specialized software which reduces the openness of the OACNC system. This paper introduces a new OACNC system based on a soft-integrated communication module. The module improves the data exchange principle in communication shared memory and is built by open API. Therefore the OACNC system can be compatible with different communication protocols between periodic and aperiodic. Then a case is proposed to test the compatibility and extensibility of the system. Finally, the prospect of the OACNC system and future research is discussed.