12-02-2007 02:13 PM
12-04-2007 08:45 AM - edited 12-04-2007 08:45 AM
Hi eemekdas,
Welcome to the forums! As I understand it, you are trying to acquire a voltage and are using the NI Example Cont Acq&Graph Votlage-Int Clk.vi to do so. In the while loop, you have added a MathScript node that has two inputs, k from the iteration counter and y which is connected to the output of the DAQmx read. You want to have the data written to a file that will let you process the data at a later time. However, you are receiving “Error -200279 occurred at DAQmx Read (Analog 1D Wfm NChan NSamp).vi:1.” Is my understanding correct?
From your description of the problem I have created the attached code which works on my computer for at least a couple of minutes without the error you were seeing. I made the assumption that you meant Y=[k y] to create the array.
The error that you are receiving is a buffer overwrite error. Here is a link with a good explanation of what is causing this and some troubleshooting steps to try.
Something to make note of is that creating an array in LabVIEW does not store the data to a file. Therefore, after the program is run, you will not be able to export and process the data later. I would suggest using File I/O to store the data, as can be seen in the Cont Acq&Graph Voltage- Write Data to file (TDMS).vi example. You can visit this site for one example of File I/O with express VIs and search the page for other good examples. However, you will need to ensure that the format you save the data in can later be opened in the environment you choose to use for processing.
Please post back if this code gives you the same error or if you have further difficulties. Good Luck.
Mallori M.