| Distributed Numerical Control(DNC) combines CNC, which is short for Computerized Numerical Control, with CAM system by using Internet technology.Using computer network technology to connect the machine tools distributed in the workshop with the computer systems and transport instructions. Traditional CNC system uses storage cards to store Numerical Control(NC) program. The storage card has a capacity ranging from dozens of KB to hundreds of megabytes and is very expensive. What is more, with the development of NC technology, completing the function of NC program is more and more complex, the volume of the program is more and more big, which is beyond the capacity of the storage card. Using Network File System(NFS) can solve the problem.NFS is developed by Sun Company and is designed as a distributed file system protocol. It is an application of Remote Procedure Call(RPC). It makes the client access NFS as easy as access the local file system by using the file handle which is compatible with the local file system interface. DNC is a system which is sensitive to users’ identification, but the design of the NFS is based on the clients’ IP address to allocate file resources. The paper’s intention is to strengthening the concept of the users in the NFS resources allocation mechanism.NS programs are usually developed in the Windows platform. It is convenient to manage NC programs to deploy the NFS service on Windows platform. The design of the NFS is based on UNIX semantics, so it is necessary to do some refactoring when being transplanted. Secondly, introducing the file locking mechanism can avoid multi-user operating at the same time which may destruct the file systems.This paper introduces the related content about NFS protocol and point out the difficulties to develop the NFS server on Windows platform.Design and implement the NFS server with a lock management.Finally,test the function and performance about the NFS server which proves the correct of the design. |
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