Hi all,
I am trying to output a digital signal from my USB-6259 Daq. I am creating an output "deck" to send to the DAQ, which is supposed to write the data out at 1000 Hz. I am simultaneously running a while loop to update the user on what is running simultaneously on the digital outputs (since I can't monitor the Dout while it is writing). I am having a couple of problems with this VI, however.
Problem #1) I can't seem to determine the correct timing source to use. In another VI I have that is simultaneously reading Analog signals and writing digital signals, I use the analog input sample clock. That doesn't work here.
Problem #2) If I use the 20 MHz Timebase, the data rushes out WAY too fast. This is the only configuration that works, however.
Problem #3) In several configurations of timing source and user-inputted variables, I get the error message "Measurements: Onboard device memory underflow. Because of system and/or bus-bandwidth limitations, the driver could not write data to the device fast enough to keep up with the device output rate.
Reduce your sample rate, alter the data transfer method (from interrupts to DMA), use a product with more onboard memory, or reduce the number of programs your computer is executing concurrently." How do I resolve this? I thought that writing the data to the DAQ MX Write VI prior to starting the task would fix this, but it did not.
Problem #4) My outputs latch high because of the buffer issue.
I'm sure that there is a simple error here -- I just haven't found it yet. Any and all information on this issue would be greatly appreciated.
Thanks for your time!!
Message Edited by Aerogoob on
07-11-2008 04:17 PM
