Data Acquisition (DAQ) and Control from Microstar Laboratories

Knowledge Base: DAPstudio

  • See the list of other topics for category DAPstudio

Q10036 Displaying data at different rates

Tags: Help, DAP, DAPL, DAPstudio, plots, graphics, processing, rate equalization

Applies to: All DAP and DAPL models, DAPstudio "live" plots

I have an application with two data rates. I have raw data at a high rate and summary data consisting of average, high, and low values of blocks of 1000 readings. I want the fast data to display in one plot, and the slow data to display in a separate plot and tabulation. When I try to send these data for display in DAPstudio, I get a few points and then the display hangs.

Why is my process hanging? And, what can I do about it?

Your process is hanging because you are merging data at two different rates into a single pipe to send to DAPstudio. Your raw data has a rate that is 1000 times faster than your summary data.

To send data to DAPstudio at differing rates use separate comm-pipes for each data stream. Any number of sources at a single data rate may be sent through one comm-pipe, but data at different rates must be sent through separate comm-pipes.

To configure a second comm-pipe for sending data, go to the Processing|Send To PC tab and click on the comm-pipe name link ($BinOut by default). Enable as many comm-pipes as you need for your separate data rates, and select the data streams to send over each link.

You can connect data from each comm-pipe to separate display windows. DAPstudio will also allow you to connect data from separate comm-pipes to a single display window, but this is unlikely to give you the results you expect. DAPstudio displays graphs and tables by sample count, and since one data stream goes 1000 times faster than the other, the data from the slow stream will not line up with the data from the faster stream.

DAPstudio allows display from the un-related comm-pipe streams for applications that have unpredictable data timing, but related data rates. Applications that use software triggering often can produce such streams,

If you want to align data rates, rather than send unrelated data over separate comm-pipe links, you can do that in DAPL. See Q10032 for an example of how to do this.


See Q10032