select the number of analog channels to be sampled in FPGA

[Mr.farmcorp]

Hi, I have cRIO and NI 9205 and I want create two VIs one for FPGA and other for HOST, from the HOST VI I will stablish the number of analog inputs of NI 9205 that the FPGA will be sampling. I know the way to sample the channels of NI 9205, but I always want to sample a different number of channels without reconfigure the FPGA and taking the decission from HOST VI.

Thank you, I hope you can help me.

Spoiler

[BillMe]

I've not used cRIO (PXI only) but I assume all the signals from the "signal conditioning" plug-ins go through the FPGA? If that's the case, then just let the FPGA sample all the inputs and then on the host side, select, e.g, index an array, the values coming back based on which channels you want to keep.

[Freelance_LV]

Hi

check the NI examples for 9205 and 9206 modules.

you will find the projects: NI 9205 - Basic IO and NI 9205 - Advanced IO. the Host vis in these project show how to configure selected number of channels for the module.

you can see the same concept for NI 9206

[BillMe]

Guess I'll go back and install cRIO and take a look at that and learn something. I may use cRIO sometime in the future.

[Akiel]

In one of my projects I had a similar problem and used billme's solution successfully. Program the fpga to sample every channel and get the data back to the host.

on the host only manipulate the data you are interested in. It is much easier to maniulate data on the host without the restraints of the fpga and also saves alot of space. Admitedly this was on a r-series. thanks for pointing out those examples btw

[Mr.farmcorp]

Hi BillMe thank you for answer. I can't just let the FPGA sample all the inputs of NI 9205 because exist something called Minimum Time Between Samples, this is a parameter of ADC, so if I read two channels is not equal to read 32 channels because the ADC have to share its time resources.

Do you have other idea?

[Mr.farmcorp]

Hi AKiel, Do you have other idea? 

[BillMe]

Did you take Freelance_LV's suggestion?

[Mr.farmcorp]

I have been testing the examples of LabVIEW (Freelance_LV's suggestion) but there isn't somenthing that give me ideas about my problem.