Hi,I am trying to acquire a signal using both channels in NI-USB- 5132 (Dual channel USB DAQ). The channel 1 is triggered on the rising edge of channel 0. The input signal frequency ranges from 50 Hz to 300 kHz. The data is acquired over a period of 20 ms with a sampling frequency of 3.125 MHz. The data is then reduced to 1024 points with a compression ratio of 61 (using custom built sample compressor taking the highest value from every segment of 61 elements). This is necessary for display and storage purposes. I am successfully able to reconstruct the compressed signal in both the channels up till 40 KHz. It is obvious that the original signal shape will be lost at higher frequencies due to compression factor. This is acceptable for the application. However, the reconstructed patterns in both the channels look different for the same signal and I am completely loosing pattern in the channel 1 after 60 KHz. Could someone please help me to find out the reason for difference in reconstructed patterns in both the channels with same input signal? Attached is the ‘VI’ for reference.Thanks in advance,Prashobh.
