how do samples per channel and data rate communicate each other?

[roxylat]

hi,        i would like to ask about what is the relationship between samples per channel and data rate for NI 9233. Is there any communication between them? If i want the data to come at every 100ms, is it concerned with any of samples per channel, data rate or both of them ? Thank you so much for your time. i am looking forward your kindly reply. With Regards,                        Roxy 

[Joseph Loo]

I am not sure which data rate you are talking about. If you read the specification, the sample rate and data rate is the same thing. In other documents, the sample rate represents the number of samples you will be taken per second. The data rate represents the total rate of data being transferred from the card. If you have multiple channels, then things are different. For example, if you have 4 channels sampling at 1K sample per second (24 bits per sample) you have have an aggregate data rate of 16 Kbytes per second. Note the different terminoly being used samples versus bytes. In your post, you mention you want data every 100 msec. You did not mention what rate or samples per second,  the number of channel involve (I believe that NI 9233 has 4 channels), or you want it continuously streamed. All of these questions come into play when you do data acquisition. I could interpret your question as 10 samples per second using only a single channel. Another possible view point is to sample 10 K samples every 100 msecs, using 2 channels. This represents 2000 data samples or 6000 bytes every 100 msecs assuming you have no delay in the data retrieval. Unless you are streaming the data, you will need to take in account of slight delays between 100 msec. As a result, the actual data rate will be < 60 Kbytes per second

[roxylat]

hi     what i mean is that there got the data rate and samples per channel in NI9233 getting started.proj example program. what do they for ? and what are the relationship of those two? Thank you so much.  With Respect,                      roxy

[StevenA]

Are you using this with FPGA or daqmx?