How do I calculate data transfer rate if I know the total number of samples/sec?

[AEI_JR]

I am attempting to specify a PXI system for making high-speed, high-channel count measurements, while remotely controlled over MXI-4.  How can I be sure that the controller is capable of transferring the data fast enough given the number of channels and expected sampling rates?

[AEI_JR · Accepted solution]

I think I figured this out, but maybe someone can back me up.  For the task at hand, I will have one PXI-4496 and four PXI-6143s all sampling at 32768 samples/sec.  4496 is 24-bit, and 6143 is 16 bit.  So,

16 channels x 32768 samples/sec/channel x 24 bits/8 = 1,048,576 bytes/sec

 +

32 channels x 32768 samples/sec/channel x 16 bits/8 = 2,097152 bytes/sec

=

3,145,728 bytes/sec, or exactly 3 MB/sec.

[Jordan F]

The MXI-4 link has a performance of up to 78Mbytes/sec. sustained so it will allow you to transfer this signal with no issues. 

MXI-4

http://www.ni.com/pdf/products/us/pc_cont_pxi_mxi4.pdf

Looking at your calculations, you are correct in how you are determining the data transfer rate.  It is important to include the number of channels, bits of resolution and the sample rate for your device when making these calculations.  Transferring 3MB/sec. will not be an issue in your application. 

[AEI_JR]

Thanks Jordan.  I must admit that I discovered the answer here:

http://zone.ni.com/devzone/cda/tut/p/id/6383