Currently I am working with a setup that contains a NI5122 digitizer and an 7966R FPGA module.
The p2p stream between the Digitizer and the FPGA is working but I want to do some digital signal processing and controlling based on the scope data.
I am a bit confused about the data format the scope streams via the P2P channel.
As most of the DSP stuff is going on in fixed-point format I would like to know what is the easiest way to get a measured analog value like 1.7V to a fxp representation that can be used in the FPGA?
Can you give an example of your data source from where you want to convert your data to fixed point to?
Do you mean the I/O node of digitizer?
BTW: Attaching an example VI (snippet) is almost always a good thing.
thanks for the reply.
So what I actually try to do is to sample analog data via my NI-5122 PXI card and stream it via p2p to the FPGA card in the same PXI reg. As I am quite new to DSP and LabView I´m a bit confused about processing the streamed data.
In my testsetup I use a 1.5V reference on my 5122 Scope input and if I just read the I16 P2P data from the FPGA and do the conversion to voltage (V=I16*gain + offset) on my host computer I get exactly the 1.5V. However for my final application I want to do the conversion from Raw I16 to voltage on FPGA side as I would like to process the data there using high throughput math functions. I tried to do it in a naive way but I end up with different results(i see an offset with a somehow nonlinear behaviour) so i must be doing something wrong 😄 .
Is there an easy way to get from the I16 Value from the scope to a fixed point representation of the voltage? E.g. Input 1.5V = 19000 (I16) = 1.4999 (fxp)
Ok i think i found the problem....
I didn´t paid enough attention to the fxp resolution as the gain of the scope is very low i need more bits to represent it.