Hi,
the ActiView acquisition is finite (read only buffer data) or continuous?
How ActiView read new data?
Read_multiple_sweeps is not inside to acquisition loop.
Thanks in advance - Salvo.
ActiView finite or continuous acquisition?
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Coen
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ActiView certainly supports continuous acquisition of data
ActiView reads new data out of the ringbuffer with subvi Act_ring.vi, whether new data is available is decided on the basis of the READ_POINTER function call, and subsequent calculations in subvi Act_Pointer.vi (all within the acquisition While loop).
The READ_MULTIPLE_SWEEPS function call initializes the ring buffer, and the actually writing of data into the ringbuffer is then started with the USB_WRITE function call. From then on, incoming data from the USB port is stored into the ringbuffer. This is an autonomous process outside LabVIEW, which is reflected by these function calls being located outside the acquisition while loop in the code diagram.
The actual 1D array representing the ringbuffer in the diagram is indeed a bit strange. A normal array that is passed into a While loop without using a shift register, will remain constant for all iterations of the loop. However, this is not the case for the ringbuffer array: this array certainly does contain new data for each new iteration. The represenation of the ringbuffer read/write process that is imposed by LabVIEW is indeed a bit confusing in this respect.
Please also note the recently introduced "light" version of ActiView, which is available at http://www.biosemi.com/download/ActiView600-Light.zip . This trimmed down version of ActiView highlights the basic communication between ActiView and the ringbuffer.
Best regards, Coen (BioSemi)
ActiView reads new data out of the ringbuffer with subvi Act_ring.vi, whether new data is available is decided on the basis of the READ_POINTER function call, and subsequent calculations in subvi Act_Pointer.vi (all within the acquisition While loop).
The READ_MULTIPLE_SWEEPS function call initializes the ring buffer, and the actually writing of data into the ringbuffer is then started with the USB_WRITE function call. From then on, incoming data from the USB port is stored into the ringbuffer. This is an autonomous process outside LabVIEW, which is reflected by these function calls being located outside the acquisition while loop in the code diagram.
The actual 1D array representing the ringbuffer in the diagram is indeed a bit strange. A normal array that is passed into a While loop without using a shift register, will remain constant for all iterations of the loop. However, this is not the case for the ringbuffer array: this array certainly does contain new data for each new iteration. The represenation of the ringbuffer read/write process that is imposed by LabVIEW is indeed a bit confusing in this respect.
Please also note the recently introduced "light" version of ActiView, which is available at http://www.biosemi.com/download/ActiView600-Light.zip . This trimmed down version of ActiView highlights the basic communication between ActiView and the ringbuffer.
Best regards, Coen (BioSemi)