Posted 01 April 2013 - 11:09 AM
Thank you for the detailed response, it certainly has helped me imporve things to some extent. What I was using was actually just the "graphing.clt" example that came with the DAQFactory install.
But I think that after your response I have a hunch what it could be: The Labjack sends enough data, that's probably not the issue, but likely sends it in USB packets. Instead of storing and smoothing them out DAQFactory probably just dumps the chunks of data as they come. I've tried adding Y Expression: 1 and X Expression: systime() and that does speed it up. When using your example with the test data it's at similar speed. However, setting the page refresh any lower than 0.1 does not increase the smoothness any further. It still is not a totally smooth rolling display like the FFTs and other things I run on the same PC. Also, it "paste on" chunks at the end, which could be because the Labjack isn't streaming.
This is something that could possibly be improved. For example, many oscilloscopes work in the same way, they transfer data over the USB in virtual RS232 manner, in chunks. Yet you still get a nice smooth roll mode display on the PC,same as on the scope itself (which usually has a much les powerful processor and a simple TFT).
Thanks again for your help.