USB Technology for USB Virtual Oscilloscopes
The proposal of usb technology is based on the use of universal connection technology to achieve a simple and fast connection of peripherals, to achieve user-friendly, cost-effective, expanding the range of peripherals connected to the pc machine, so that the expansion of the pc's functionality has become very easy and can minimise the user's need for computer technology, so that all peripherals have become the so-called "fool" type of device. "The specification of usb can provide different options for different performance-price ratio requirements to meet the different systems and components and the corresponding different functions, the main advantages are as follows.
(1) end-user ease of use.
(2) Wide range of applications.
(3) Synchronous transmission bandwidth.
(4) Flexibility.
The usb technology has an open, non-profit specification and is widely supported by industry. It has been widely used in the fields of digital imaging, telephone speech synthesis, interactive multimedia, and consumer electronics.
System structure of USB virtual oscilloscope
The structure of a complete virtual instrument system is generally divided into four layers:
1. test management level users use the application developed by the virtual instrument manufacturer to form their own set of test instruments. This is one of the advantages of virtual instruments, which can easily enable users to build their own test instruments according to their own needs, their own style.
2. Application (programme) development layer provided by the manufacturer of software development tools, such as NI (NATIONALINSTRUMENTS) company's LabVIEW software, LabWindows/CVI software. Users can use this type of software for deep development to extend the original function of the instrument.
3. Instrument driver layer developed by the manufacturer, for different types of instruments have different driver interfaces. In order to provide users with convenient, easy to use instrument drivers, Tektronix, Hewlett-Packard and the United States National Instruments and other 35 of the world's largest instrument companies set up a VXIplug & play system alliance, and the launch of VISA (Virtu-alInstrumentSoftwareArchitecture) standard.
4. I / O bus driver layer developed by the manufacturer, for different types of actual instruments through the same standard bus connected to form a complete test system, such as the widely used VXI (open measurement system) bus system.
