Error 200279-increase buffer size

[ashishvj]

Hi everyone

I was hoping that somebody could help me

I am new to LabView and am currently using the Express VI's along with a PCI6220 DAQ card

I am trying to acquire signal through 4 channels at a sampling frequency of 50 KHZ at this time I get the error 200279.

The VI works while when acquiring the signal it is only when i start saving it to a file after a few seconds it generates the error

At 20KHz it work all right and there  are no problems at all either while acquisition or while writing to a file

I read the forums and tried to decrease the read the sample faster by decreasing the number of samples to read, but still the same problem

persists.

I am not quite sure how to increase the buffer size (does it not adjust automatically according to the sampling freq)

Thanks a lot

Ashish J

[devchander]

Instead of using express VI's , use any DAQmx VI's that you will find in examples

find example>>hardware input output>>DAQmx>>Analog measurements>>voltage folder and choose any relevant example.

I suggest you go for a binary acq program ( for acquiring, writing and reading) for a high sampling rate like 50K

[Jesse_O]

Hello Ashish J,

As devchander pointed out, using Express VIs will slow down your code.  There is a good shipping example called 'Cont Acq&Graph Voltage-To File(Binary).vi' located in NI example finder.  You can find this file by selecting Help >> Find Examples from within LabVIEW.  When example finder appears, make sure the browse tab is selected and select Hardware Input and Output >> DAQmx >> Data Measurement >> Voltage >> Cont Acq&Graph Voltage - To File(Binary).vi.

This VI demonstrates how to use the DAQmx VIs and the write to binary file VIs.  I have tested this application at the 50KHz rate you mentioned.  Keep in mind the format this example writes the data to file.  It might not be in a useful format for you, however you can modify this to put it in a useful format for you.  If you keep the binary file format it is not human readable however it will consume much less disk space than an ASCII file will.

I would expect that you should be able use the DAQmx Express VI, however the Write LabVIEW measurement file or the write spreadsheet file are probably causing your problems.

Regards,

Jesse O.
Applications Engineering
National Instruments

[marcelappb]

Hi,

I have the same problem...

And I'm using the example Cont Acq&Graph Voltage - Write Data to File (TDMS).vi.

I need a continuous acquisition, using 4 channels, and at least 1MS/s (rate), and record this for trirty minutes or more.

But the same error occurs.

Can you help me?

How I can acquire this datas with a big rate like 1MS/s and record?

Thanks