OPEN ARCHITECTURE CNC SYSTEM HITCNC AND KEY TECHNOLOGY

Aiming at the characteristics of modularity and reconfigurable in open architecture computer numerical control （CNC） system, the open architecture CNC system, Harbin Institute of Tech- nology computer numerical control （HITCNC）, is researched and manufactured based on the interface standards. The system＇s external interfaces are coincident with the corresponding international standards, and the internal interfaces follow the open modular architecture controller （OMAC） agreement. In the research and manufacturing process, object-oriented technology is used to ensure the openness of the HITCNC, and static programming is applied in the CNC system according to the idea of modularization disassembly. The HITCNC also actualizes real-time and unreal-time modules adopting real-time dynamical linked library （RTDLL） and component object model （COM）. Finite state ma- chine （FSM） is adopted to do dynamically modeling of HITCNC. The complete separation between the software and the hardware is achieved in the HITCNC by applying the SoftSERCANS technique. The application of the above key techniques decreases the programming workload greatly, and uses software programs replacing hardware functions, which offers plenty technique ensures for the openness of HITCNC. Finally, based on the HITCNC, a three-dimensional milling system is established. On the system, series experiments are done to validate the expandability and interchangeability of HITCNC. The results of the experiments show that the established open architecture CNC system HITCNC is correct and feasible, and has good openness.

NASSN:a NAS-based storage network

With the digital information and application requirement on the Internet increasing fleetly nowadays,it is urgent to work out a network storage system with a large capacity,a high availability and scalability.To solve the above-mentioned issues,a NAS-based storage network(for short NASSN)has been designed.Firstly,the NASSN integrates multi-NAS,iNAS(an iSCSI-based NAS)and enterprise SAN with the help of storage virtualization,which can provide a greater capacity and better scalability.Secondly,the NASSN can provide high availability with the help of server and storage subsystem redundancy technologies.Thirdly,the NASSN simultaneously serves for both the file I/O and the block I/O with the help of an iSCSI module,which has the advantages of NAS and SAN.Finally,the NASSN can provide higher I/O speed by a high network-attached channel which implements the direct data transfer between the storage device and client.In the experiments,the NASSN has ultra-high-throughput for both of the file I/O requests and the block I/O requests.

Design and Implementation of a Fibre Channel Target Driver Supporting SCSI

Fibre channel storage area networks (FC-SAN) are effective solutions to address storage man- agement problems caused by very large volumes of data. But the expense of fibre channel devices limits FC-SAN applications. The use of IP networks instead of fibre channel networks will reduce SAN cost, but will also reduce the performance. Therefore, small computer system interface (SCSI) devices were consid- ered to replace FC disks to reduce the SAN cost. A driver for the FC network adapter and the FC target, de- signed and implemented to support this structure, obeys the SCSI protocol and works in target mode with 200 MB/s bandwidth. The FC target architecture and implementation were compared with the FC initiator. The SCSI command transfer process in the FC layer was described. The performance test results show that the maximum I/O throughput reachs 167 MB/s for read requests and 196 MB/s for write requests (FC band- width is 200 MB/s), verifying that the FC target is very efficient. The modularization, efficiency, and low cost of the FC target will enable SAN and fibre channel to be more widely used in applications.