The specs for the NI model 4552 DSA card realtime octave addon are listed as max 10KHz band for one-third octave on 4 chan

[DonH]

nels (20KHz for 2 channels). Does this limitation apply only for real-time operation? In other words, if I was satisfied with non-realtime analysis of a steady-state input signal, could I get higher bandwidth, say, up to the 50 KHz one-third octave band?

[Jace C]

nels (20KHz for 2 channels). Does this limitation apply only for real-time operation? In other words, if I was satisfied with non-realtime analysis of a steady-state input signal, could I get higher bandwidth, say, up to the 50 KHz one-third octave band?DonH,
This limitation does only apply for real-time operation. The DSA 4552 is capable of sampling at up to 204.8 Ksamples/sec on each channel. If you do not need real-time processing, you can use any sampling rate available for the NI 4552. In order to do 1/3 octave analysis in software, you will need the sound and vibration toolset. You can find this at:
http://sine.ni.com/apps/we/nioc.vp?lang=US&pc=mn&cid=3122

[DonH]

nels (20KHz for 2 channels). Does this limitation apply only for real-time operation? In other words, if I was satisfied with non-realtime analysis of a steady-state input signal, could I get higher bandwidth, say, up to the 50 KHz one-third octave band?JaceC, thanks for the response. I understand that I can compute the third-octave data in the computer with the S&V toolset. However, my question is: can my entire spectral (10 Hz to 40 KHz) be computed by the 4552 board's processor? I understand that the analog sampling and computatiion process will not be real time, that is, that some time data may be "missed", but I can tolerate this in some of my applications.

[Jace C]

nels (20KHz for 2 channels). Does this limitation apply only for real-time operation? In other words, if I was satisfied with non-realtime analysis of a steady-state input signal, could I get higher bandwidth, say, up to the 50 KHz one-third octave band?DonH,
This is a good question. The analog sampling is real-time and hardware controlled regardless of whether or not you are doing hardware analyzing. You are not at risk for missing any data points or affecting the sampling speed. If your computer is not fast enough to analyze the data as it comes in, you could stream the data to disk for analyzation once the acquisition is through. You will know the computer is not fast enough if you got a buffer error during the acquisition. Basically, you are not compromising the quality of data at all. It will just take longer to get results.

[MLachaine]

nels (20KHz for 2 channels). Does this limitation apply only for real-time operation? In other words, if I was satisfied with non-realtime analysis of a steady-state input signal, could I get higher bandwidth, say, up to the 50 KHz one-third octave band?I did notice distortion in the time domain data if you try to do real time onboard analysis and zoom band analysis simultenaously. More channel you use (or zoom fft onboard) you have to reduce to upper F limit.