Our company's All information AE system is mainly aimed at the field of acoustic emission research. The communication interface uses the USB2.0 interface, which can achieve a continuous data pass rate of up to 48MB/S. The achievable collection modes are as follows:

    1) Using two channels, a sampling rate of 10M can be used to fully record the acoustic emission waveform.
    2) Using four channels, up to a sampling rate of 6M can be used to fully record the acoustic emission waveform.
    3) Using eight channels, up to a sampling rate of 3M can be used to fully record the acoustic emission waveform.

    We adopt synchronous transmission mode. The USB2.0 protocol stipulates that the minimum transmission time unit for synchronous transmission is microframe. A microframe is one eighth of a millisecond, or 125uS. Each microframe can transmit 6 synchronous events, with each event being 1024 bytes. Transmit per second: 1000 * 8 * 6 * 1024=49152000 bytes of data, approximately 49.2MB/S. All AD acquisition channels can generate up to 48MB/S of data per second, while the USB channel provides a bandwidth of 49.2MB/S, which technically ensures continuous and reliable transmission without losing any sampling data.

    For batch transmission mode, it is also possible to set each microframe to transmit 6 batch events, with 1024 bytes per event. But this is the most ideal data, which is the speed that can be achieved when the computer operating system is completely idle. The batch transfer mode can be called the "adaptive" mode, which can reach a high speed (48MB/S) when the computer is idle, but it will be slow when running other programs on the computer, which can be experienced when we use a mobile hard drive. Therefore, if batch mode transmission is chosen, a large capacity data buffer must be set at the data sending end, with an estimated capacity of over 1GB (such as DDR chips). Even so, it is difficult to ensure that data does not overflow.

   Another issue: As we all know, the Windows system itself is a non real-time operating system, and user applications cannot control real-time operations on hardware. It is difficult to clarify what the backend operating system is currently doing. So, how can our company's acoustic emission instrument ensure that data does not overflow? When we connect the USB acoustic emission device with synchronous transmission mode to the computer, the operating system will immediately read the information that the acoustic emission device needs to establish a communication protocol, and use this information to set the USB controller on the computer motherboard. When communication is started, the USB controller of the motherboard will automatically read the data of the acoustic emission instrument and place the data in the pre-set memory, without the intervention of the operating system. This ensures that the collected data is transmitted in real-time to the computer's memory.