Configuring Analog Voltage Measurement Using USB 6008 and DAQ Assistant

[schmiggy1279]

Hi,

I'm new to this so be patient with me. I'm using Labview 8.6 with a windows 7 PC. I am using a USB 6008. I have 4.5V input to AI0+ and grounded AI0- from a battery source. I have configured the DAQ assistant in Labview. Signal input range is -12 to +12V. Terminal Configuration is differential. Acquisition mode is N samples. Samples to read is 5 and rate is 1KHz. The data output from the DAQ assistant goes to a waveform graph. However, no matter how I change the sample number or rate the program bombs out with the following error.

Error -200361 occurred at DAQmx Read (Analog 1D Wfm NChan NSamp).vi:3

Possible reason(s):

Measurements: Onboard device memory overflow. Because of system and/or

bus-bandwidth limitations, the driver could not read data from the device

fast enough to keep up with the device throughput.Reduce the sample rate,

or reduce the number of programs your computer is executing concurrently.

I have looked on different websites but no joy...

Please help...

[Tim_S]

Acquisition mode is N samples. Samples to read is 5 and rate is 1KHz. The data output from the DAQ assistant goes to a waveform graph. However, no matter how I change the sample number or rate the program bombs out with the following error.

Error -200361 occurred at DAQmx Read (Analog 1D Wfm NChan NSamp).vi:3

First, don't trust the PC to read data every 5 msec; that's just too fast for a Windows based system. Yes, Windows can do it, but all it takes is someone opening a large file to mess up your data acquisition. You're better off with 1 kHz sample rate and 100 sample read (read every tenth of a second).

Second, is the DAQ the only thing in the system? Is there anything that is creating a time delay? Event structure? Wait? Wait until multiple? It's possible that you are not reading the data fast enough simply because you're not getting around to it in time.

Third, people can help far more readily you if you post the code you're working with. If it's too big, make a small example that demonstrates the issue.

Tim