【摘要】 虚拟仪器是一种新的仪器模式 ,是仪器领域的一场革命。虚拟仪器软件结构 (VirtualInstrument Software Architecture,VISA)是 VXI plug& play联盟制定的 VXI总线虚拟仪器标准化 I/ O控制软件。作为 VISA的核心 ,资源管理器是其它所有 VISA函数工作的平台 ,它负责管理、控制和分配VISA资源。事件处理机制是 VISA机制体系中重要的一部分 ,它负责捕获、通知和处理 VISA内部和外部需要应用程序响应的事件 ,其中 ,回调机制用于处理需要立即响应事件 ,而队列机制用于处理不需要立即响应的事件。为了完成内嵌式控制机 VISA I/ O函数 ,必须编写虚拟设备驱动器 (Vx D) ,用于在Win95 / 98环境下访问物理地址和处理硬件中断。更多还原

【Abstract】 The virtual instrument is a new model of instruments and causes a revolution in the field of instruments. Virtual instrument software architecture(VISA)is a standard I/O interface software developed by VXI plug&play systems alliance. As the key of VISA, the resource manager is the table of all other VISA functions and is responsible for managing resource, controlling resource and distributing resource. Events mechanism is responsible for trapping, notifying and processing internal and external events. The queuing mechanism in VISA gives an application the flexibility to receive events only when it requests them. The callback mechanism allows applications to install functions that can be called back when a particular event type is received. It is necessary to write Virtual Device Drivers (VxD) for the VISA I/O functions of the embeded controller to access physical address and deal with hardware interrupt.更多还原