Error 200141 occurs when running concurrent VIs.

[VI_Joe]

I want to make an acceleration measurement and a displacement measurement concurrently using the cDAQ-9172 chassis.  I am using the 9233 in slot 1 for the acceleration measurement.  I am using the 9401 in slot 5 to count pulses for the displacement measurement.  Both measurements are being made at the same time that I’m generating a 12V pulse of 10ms duration with the 9472 in slot 4. The acceleration measurement works fine and the displacement measurement works fine when run separately.  However, when run concurrently, about every fifth time I run the program, I get error 200141 – “Data was overwritten before it could be read by the system.”   This error is associated with the displacement measurement.  When run as a stand-alone VI, the displacement VI runs reliably with the sampling rate set at 80MHz.  When run concurrently with the acceleration measurement, it fails when running at 100KHz.  I am using DAQmx VIs and I am using a computer with USB 2.0.  I have attached 2 displacement VIs that exhibit the same results.  One VI does the read inside a while loop and the other doesn’t. Is it reasonable to expect to run multiple VIs concurrently.  Is there anything I can try to eliminate error 200141? 

Thanks in advance.

[Jordan F]

Hi,

I am curious if you are running two different LabVIEW programs to make the measurements with the different Modules in the cDAQ chassis.  If so, I would recommend to run the acquisition tasks in the same program to see if you have the same error occur.  Also, I am not sure what sampling rate you are using for the acceleration measurement.  The specifications for the cDAQ chassis is that it is capable of streaming up to 5MS/s (this is ideal) to the computer memory.  This means that the more samples you are taking in with the cDAQ the harder it will be to stream this to the computer memory without reaching the transfer capacity.   

[jdude]

I am running two separate VIs in the same program.  The sampling rate for the acceleration measurement is 1KHz

[Jordan F]

Could you post the VIs that give you the error for me to try out on my machine?  Were you seeing the errors on the VIs that you posted initially?  If I can recreate the error I will know more about how to help solve this problem.