Displaying and saving multichannel waveforms using PCI-6221 DAQmx card

[nins]

I am trying to obtain voltage readings at 8000 kHz from 9 channels using a PCI-6221 DAQmx card. The waveforms are to be displayed on individual charts while being saved. I have run into problems when I have 4 channels reading in at the same time. The charts stop displaying the data. Since the program will be running within another program where video acquisition is being done, space/buffer size is a very large consideration. If anyone can offer any suggestions about being able to display and save this data without losing seconds of information, the help would be appreciated.

Thanks,
Nina

[sergesl]

Hello Nins,

The first thing to notice is that you are going far beyond the specifications of the 6221 if in fact you are sampling at 8000 kHz. Something I can tell you is that when you are performing fast acquisitions and processing the data at the same time, it is sometimes advised to have an acquisition loop (procucer loop) and a processing loop (consumer loop) and transfer data between the two. That way, you can put a wait in the consumer loop and use a waveform graph to plot the data rather than using a Chart wich requires memory.
Hope this helps some...

[nins]

Thanks! I'll give that a try!

Nina