Stream Data from NI-6534 to Disk

[joe5213]

Hello, I'm still a newbie with Labiew, just know enough to be dangerous. But I'm trying to develop a small application to stream data from a NI-6534 data acquisition card to disk. My application samples the data at 20Mhz and the data is 16-bits wide. I've set up the application to save the data to a binary file. My goal is to stream minutes of data to disk, maybe 10-minutes of data. I will be setting up a RAID to reduce the time spent saving to disk. The problem I'm running into is when I run my application it will run for a short time (6 seconds or so) and then stop. There are not any reported errors so I'm not sure what the problem could be. I hope there are some experts out there who may have done something similar or could briefly look over my application and give me some suggestions.

thank you very  much,

joe

[joe5213]

Hello, I found a bug in my program and have removed it, but now when I run my application it gives me an error message. I've attached a graphic of the error message and my application. I hope someone can give me some pointers on streaming data to disk.

thanks,

joe

[Justin_M]

Hi Joe,

Error -200279 is actually a DAQmx error.  In the future, please post questions about hardware or hardware drivers to one of the hardware forum boards.  Because you are using the 6534 in your case, I'd suggest the Digital I/O forum.  You'll get many more responses to your questions, AND it will make it easier for others to find and learn from your post.

I can tell you that error -200279 means that you are not reading the data out of your buffer fast enough, so it is filling up and eventually being written over, which is what throws the error.  See the following KnowledgeBase, which addresses the issue:

(DAQmx) Error -200279 During a Continuous, Buffered Acquisition

-Justin

[joe5213]

Justin,

Thank you very much for your suggestion. Streaming data to disk at 20Mhz has been a challenge and I'm learning a lot. Looks like I need to get my RAID system installed that might make things run faster. I've read a few other newgroups and they mentioned that in most cases the bottleneck is writing to disk. I've ordered two SATA drives and I'll configure them to be a RAID disk, I hope that will solve my problem. Have you streamed data onto a disk at 20Mhz before, or have you known anyone to do such a task before? I did find another example of streaming data to disk, Pattern_Input_to_Binary_File_(cont)_Benchmark.vi. When I run this .vi it shows that I'm unable to stream data at 20Mhz at 32-bits. But I am able to stream 16-bits in at 20Mhz, but I need 32-bits.

Thanks for the help, I'll try to get my RAID installed, if that doesn't solve my problem, them I may have to try a Matrox Frame Grabber card to capture the data. By the way, I don't claim to be a Labiew expert, but if you have any suggestions on my application, please let me know. I'll check out the link you suggested.

thanks,

joe