DeviceNet is a mainstream field bus in industrial automation.Its application has been broadening because of its good performance,high reliability,high efficiency and low cost.However,the research and development on DeviceNet in China is far behind the market request.This work focus on the development of DeviceNet communication interface for master devices.The interface drivers,the protocol application software which realize DeviceNet specification are successfully programmed.This thesis describes DeviceNet Specification with an emphasis on its communication protocol including message,device profile and predefined master/slave connection set,constitutes a technical requirement of a general DeviceNet communication interface for master device;and finally designs and realizes the communication interface.