【作者】 童永霞；

【导师】 王学伟；

【作者基本信息】 北京化工大学 ， 计算机应用技术， 2009， 硕士

【摘要】 虚拟仪器软件体系结构(Virtual Instrumentation Software Architecture,简称VISA)是标准化的I/O函数库及相关规范的总称,它屏蔽了用户对于硬件接口的直接操作,是计算机与仪器之间的软件层连接。VISA作为一个标准,独立于硬件设备、接口、操作系统和具体的编程语言,它只公布了其中各个函数的原型,而对如何实现这些功能并未作任何说明。VISA面向仪器而不是面向接口总线,它与仪器的硬件相关,所以VISA函数库开发者需要开发出与特定的硬件相关的函数。本文以实验室开发的USB-GPIB控制器及多台设备为硬件基础,首先,针对国内现有的VISA函数库支持的物理接口种类较国外少的问题,提出了一种链表式的资源管理与组织方法,利用该方法设计VISA函数库的内部结构,可以方便地扩充VISA支持的接口种类,使现有的VISA函数库具有良好的向后兼容能力。通过在实验室前期项目中开发的针对GPIB接口的VISA函数库中扩展了对RS-232接口的驱动功能,验证了该方法的有效性和合理性。文中通过对VISA函数库中几个关键函数的介绍详述了链表式资源管理与组织的方法。事件机制作为VISA系统的一个重要的机制,在国内也有一定的研究,但尚未有文章详尽细致全面地论述其原理及实现方法。鉴于此,本文还对VISA事件机制进行了深入研究,通过详细阐述VISA事件机制的原理以及具体实现方法,再加上对VISA标准中事件相关的六个函数的实现进行详细介绍,完善而系统地阐述了VISA事件机制及其实现。最后,给出了设计开发的VISA函数库在VisualC++6.0环境中的应用实例。更多还原

【Abstract】 Virtual Instrumentation Software Architecture VISA is a set of the standardized I/O function library and its correlative criterion. VISA is a software connection between the conmputer and devices. As a standard, VISA independent of devices, interfaces, operating system and specific programming languages. It only publicized the prototype of each function and how to realize these functions was not specified. VISA faces the equipment but interface bus. It relates to the hardware of the devices, so the developer of VISA function library should develop the VISA functions related to specific hardware.Based on the USB-GPIB interface controller that was developed by my lab and some other hardware devices, this research subject accomplished those tasks as follows. Firstly, for the interface type VISA function library supported in domestic is limited, this dissertation proposed a method that can manage and organize the resources in the VISA by a list. By using this method, we can expediently extend the types of interfaces VISA supports and make the VISA library can own a very good backward compatibility. The rationality and validity of this method has been validated by adding the drive function on RS-232 interface into the VISA library which has been developed by my lab.As a very important mechanism in the VISA, Event mechanism has been researched in domestic, but its principles and how it fulfilled has not been detailed in any paper. For this reason, the author gave an in-depth study of VISA event mechanism. This dissertation systemically showed what the VISA is and how it can be actualized by specifying the principle of VISA event mechanism and the way how those six funcitions related to the VISA event mechanism were fulfilled. Finally, this dissertation showed the application in the Visual C++ 6.0 development environment which based on the VISA function library.更多还原