I don't know how to scale my wavechart to show
my real-time signal. For example, in this application, I would like to
display a 2 VPP 100 Hz sine-wave voltage signal on my wavechart. I set
my Host vi loop rate to 10 ms, while my FPGA sample rate is 100 KHz.
What should I do is I want my X-axis has ten unit length and it
reprents 10 ms, in which case the frame should contain one period of
the sine wave? And I suppose if I change the denominator into 1000,
the rate of change should be in second. However, seems it doesn't work
in this way. I attach project and both host and fpga vi.
Also
I try to scale Y axis to show +/-1V of 2VPP signal. I used the scaling
factor offered by the example vi, but seems it's not right. the
formula is (1V*x)/32767. I don't know what 32767 stands for in the
example vi: it doesn't seem to me the greatest double precision
floating number.
Thank you very much for your help.
I got the recommendation from Mr Robbob as the following
"
My recommendation: Convert your number to
Fixed Point on the FPGA and do your scaling there. Change your FIFO to
handle Fixed-Point numbers of the required Integer and Decimal bit
values. FPGA is fast and great for conversions like that. That way,
when you read your FIFO on the RT side, your values are already scaled
properly and you can wire directly into your graph.
"
However, could someone please provide me with more information and details how to implement this both on fpga and host vi? Also, would you please give me some instructions on the scaling of X-axis to show real time? Thank you very much.
