12-26-2006 01:57 PM
12-27-2006
05:28 PM
- last edited on
03-27-2024
05:34 PM
by
Content Cleaner
Hi Dave,
This error can occur for a number of reasons, but it is usually because the USB onboard FIFO cannot keep up with your data acquisition rate. The following Knowledge Base (KB) article describes this behavior.
USB-6008/6009 Error -200361: Buffer Overflow Error
After going through that KB, check to see if there’s any correlation between the number of programs that you have running and the frequency of the crashes. If you see a pattern, then this is probably the problem, and you’ll just need to keep extraneous programs minimized during acquisition.
I hope this helps. Post back with your results.
Regards,
Ed W.
Applications Engineer
National Instruments
12-28-2006 06:59 AM
Hi Ed,
Thank you for the KB. It describes my problem. For example, after I posted the original question, I placed a USB memory stick in the computer while the application was running. I promptly got the -200361 error and that told me a lot right there.
Here's the application: We have a customer with a number of research vessels that tows instrumentation in the ocean. We make sensors (load cells) that monitor the line tension. Occasionally they break a line and they feel the breakage is due to surges or shock loads that the tension display system cannot show. They contracted us to provide a load peak monitor system to graphically display the surges and peaks in line tension along with peak duration. This is a perfect application for LabVIEW. Obviously this will require continuous data acquisition for several hours. I’m streaming the acquired data to a datalog file for long-term (i.e. 12 hours) program stability.
I chose the USB device because the customer will be providing their own laptop computer and I thought using a USB port would be a convenient way to capture data. The USB-6009 product was chosen for its higher capture rate. (The design goal is to capture at least 1000 samples per second.) Originally I set the DAQmx Read Rate to 10,000, which made the application unstable. I lowered the rate to 6,000, which resulted in an intermittent -200361 error. I lowered the rate further to 4,000 and now I very rarely get the error. Lowering the rate to 2,000 or less make the system not responsive enough. Maybe the answer is to set the rate to 3,000 and call it good.
My concern however is the customer’s laptop. Who knows what performance we are going to get? I am going to define the read rate in a *.ini file so we can quickly make adjustments in the field. In the meantime however I wonder if there is a more appropriate product that I should use. I’m not stuck using the USB-6009 device.
We are monitoring 4 analog channels; although only one at a time. The resolution is not critical, but I’d like at least 14 bit. The goal is to be able to capture and process at least 1000 samples per second. The sensor output is a 4-20mA signal, which of course I can easily convert to a voltage signal. Is there a USB device with an increased FIFO buffer that would be better suited for this application? Using a PCMCIA option is much less preferred. (Again I don’t know what computer hardware they are going to give me to use.) The project does not have the budget for RT hardware.
Thank you for your response.
Dave
01-02-2007
11:53 AM
- last edited on
03-27-2024
05:34 PM
by
Content Cleaner
Hi Dave,
I would recommend something from our USB Bus-Powered M Series Multifunction DAQ product line. These devices have greater functionality and are much more robust than the low-cost USB-6008/6009 series.
Post back if you have any further questions. Thanks!
Ed W.
Applications Engineer
National Instruments