USB-6218 transfer speed to PC

[DavidHocking]

Hi guys,

I hope to sample 10 channels at 10Hz for around 1 hour, into Labview 8, on a relatively new dual-core desktop PC.

I first tried an Agilent34970a, and found that although it could continuously scan fast enough, the GPIB transfer speed into Labview was too slow and the PC couldn't keep up.

So I plan to set up a continuous scan on a USB-6218, and then read the timestamped data via USB into Labview.   

Having read about NI's 'usb sample streaming', my question is:  roughly how fast will the data transfer over USB? Will I be able to transfer 10 timestamped channels at 10Hz continuously into Labview, and still have processor cycles left over for the other .VI duties such as writing to file and updating the screen.

The reason I am aiming for USB rather than PCI/PXI is because I am concerned about interference from the computer affecting my signals.  I will be reading analog voltages only in the +-10V range. 

Thanks for your insight. 

Message Edited by DavidHocking on 01-24-2010 10:12 PM

[Dennis_Knutson · Accepted solution]

You can acquire and save at rates many orders of magnitude greater than 10 Hz. A good way to ensure that you can keep up is with a producer/consumer architecture so that the file writes are done in a separate loop. Saving to binary is also much faster than saving to text. So, the design of the program is important as well as the hardware you use.

[DavidHocking]

Thank you Dennis, understood.