During this time, I have been doing the test of the LabVIEW and USB device. The object is a solid digital oscilloscope, GDS-815C. LabVIEW provides two USB interface functions, USB Control In.vi, and USB Control out.vi, but these two can only be used with 0 endpoint communication with USB devices, and their parameters are not exactly the same as USB standard documents. So actually use these two functions and 0 endpoint communication of the USB device, plus the LabVIEW only provides plug-and-play support for the USB device of the test and measurement class, put it in the USB INSTR type, All of the other devices are summarized in the USB RAW type, and actual communication is still performed through Visa. And VISA must upgrade to version 3.2 or more to communicate with the USB device. For USB RAW types, you must use the Visa Driver Development Wizard to install the device to tell LabVIEW and Windows have such a device. Premise Just know the VID and PID number of the device, these two numbers can be found from the drivers provided by the device. Do not need to install the drivers provided by the manufacturer without installing, installing the equipment provided by the manufacturer in the LabVIEW, cannot communicate with the device. Because the manufacturer can customize the third layer protocol in accordance with USB technical documentation, the relevant data cannot be obtained in LabVIEW.
Since Duan Wei does not provide a USB instruction set, only one sample program is provided, and only the current waveform data can be displayed, so I use USB Sniffer to intercept USB packets to get relevant instructions. When using USB Sniffer, it is not noticed that it uses a number represented by the data package corresponding to the USB packet, and uses Down and Up to distinguish it, and it The total number of packets displayed separately, that is, when Sniffer is suspended at 844 this package, it is actually corresponding to 422 (of course, there may be a nearby data packet, should be there may be only upstream Or only when the data packet is downloaded, for example, when communicating in the use of interrupt, it will receive the actual corresponding to 422 results very late.) So, I have been looking around 844. The relevant directive is of course not found. Directive is really found when this situation is found. Communication is performed with the device via VISA.
