Hi everyone, I have made this vi which performs following operations: 1) Data Acquisition using DAQmx read at 500k S/s (Producer loop) 2) Data logging in a parallel loop (Consumer loop) in multiple files in TDMS format. 3) Data generation at analog output using DAQmx write at 500k S/s. I have used the DAQmx write in non-regeneration mode. So, in the first second, I am sending 1msec burst of sine wave with 5k Hz frequency followed by zero voltage for remaining 1sec-1msec= 0.999sec. In the 2nd second, I am sending 1msec burst of sine wave with 5+1=6k Hz frequency followed by zero voltage for remaining 1sec-1msec= 0.999sec.................and in this way, I am increasing the frequency of burst by 1K Hz to reach 50k Hz. It is a kind of frequency sweep. After which I want to stop generation and acquisition simultaneously. 4) The acquisition and generation is completely synchronized by sharing the 'ao' sample clock with the analog input and by triggering reading operation using 'ao' start trigger. I have few doubts related to this vi: 1) Is it good to keep DAQmx read and DAQmx write in two parallel loops? In most of the online examples, I have seen that people have kept daqmx read and daqmx write in the same loop. In my case, the generated data needs to be updated every second and hence complex function generator sub vi has to be connected to the daqmx write inside the loop. When I am keeping both daqmx read and daqmx write in the same loop, may be due to the complexity and delay caused by this function generator sub vi, this error is occurring ("The application is not able to keep up with the hardware acquisition"). I think the DAQmx read is not called fast enough (due to the slow writing operation) in the loop. That is why, I put daqmx read and daqmx write in two parallel loops. It is working fine but I don't know whether it is good and efficient way of doing things or not because I have not seen any online example of that kind. 2) What should be values of these parameters: 1) Number of Samples per channel in 'DAQmx Timing'' 2) Number of Samples per channel in 'DAQmx Read'. The sampling frequency is 500K S/s. Till now in all my previous data acquisition projects, I have always left these two parameters unconnected and error never occurred. But in this project, if I am not assigning any value to these parameters, weird errors are occurring. Please have a look at my vi (attached) and suggest me the solutions. I am using USB 6356 board.

Hello Amartansh13, yes, both tasks run synchronous You have done the right, sharing the sample clock and use a start trigger. only the itteration of the two loops are differen, but with the shared sample clock, they are synchroniced.

LabVIEW

Optimum parameter selections for data acquisition and generation tasks in parallel loops.

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Thanks a lot for your reply.

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Optimum parameter selections for data acquisition and generation tasks in parallel loops.

Re: Optimum parameter selections for data acquisition and generation tasks in parallel loops.