Design And Implementation Of VISA Library Of LXI-VXI Slot 0 Controller

With the development of Internet communication technology, a new type of integrated testing technology of LXI bus based on LAN is developed. Compared with the traditional GPIB, VXI, PXI bus, LXI bus has the advantages of high performance, small size, low cost, so it has been widely recognized by the market as a new generation of representative bus. In order to make full use of the traditional bus instrument, it is a trend to construct a hybrid bus test system with the traditional bus and LXI bus instrument. The core of the platform software of hybrid test system is the Virtual Instrument Software Architecture Library(VISA Library). So it is imperative to develop the VISA library to support the LXI interface.In the traditional measurement bus technology, the measuring instruments are usually used as the peripheral of the master computer. We need to develop a separate device driver and interrupt service is development based on Windows API functions. The LXI interface based on LAN is used as a remote terminal in the network, which can be controlled by a number of master computers simultaneously. Therefore, new changes have occurred in the processing of interrupt events. The new requirements of information synchronization, resource locking mechanism, session management and so on are also presented.In this paper the project demand analysis is carried on, so does the overall design of the LXI/VXI hybrid test system software structure and hardware platform. Then this paper put forward the design scheme of the visa library internal resource management structure and session management structure. The visa norms on the basis of research and analysis to achieve the visa resource management function, the basic functions of IO operation, formatting IO operations function, memory IO operations function, completed the visa of the internal functions of: property mechanism, locking mechanism and the event mechanism. The implemented VISA functions in the thesis varies from resource management operation, basic IO operations, format IO operations, memory IO operations and so on. We also achieve the inside function in VISA: the attribute mechanism, the locking mechanism, the event mechanism.Finally, in order to verify the rationality and performance of the VISA library, we did a lot of tests. First, the function of resource discovery was tested, and then the function and performance test of different types of VXI instruments were carried out. Finally, the whole system was tested in the case of multi chassis interconnection.The test results show that the VISA library developed by this research has good compatibility with the existing software and hardware of the test platform. Identified by the expert group and review, the realization of the requirement analysis phase of the proposed all functional requirements and indicators that the design scheme is reasonable, expanded the domestic visa library support interface, can be used to construct multipurpose universal test platform.