I have created a project that continuously reads a voltage acquired from a load cell (strain gauge) using a cDAQ NI-9224 module in an NI-9171 chassis. Simultaneously, the program reads deflection data from laser deflection sensors through a third-party interface device connected to the PC via USB. I would like to roughly align in time the two data streams, but I am having a difficult time doing so. The laser sensor interface accepts a hardware trigger, but cannot generate one, so I can't use it to trigger the DAQmx device. So far, I have tried to find the t0 offset between the first set of samples from both interfaces. I then used a DAQmx Read property node to set the Offset of the load cell Relative To the next set of samples to roughly align with t0 of the next set of samples from the laser sensors. The program then reads another set of samples. Then, I used a DAQmx Read property node again to set the next buffer read position to Current Read Position to move the beginning of all subsequent reads to just after the last sample previously returned. This, however, didn't solve the problem, as each subsequent DAQmx Read takes a long time to complete, and reads from the buffer can't keep up with the acquisition. The program is quite complex and I am working on creating a simplified version of it to post here. I just wanted to start a post in case anyone has any immediate ideas.

I figured out how to accomplish my goal using LabVIEW code instead of the more elegant hardware solution proposed by @santo_13. I am hesitant to mark the suggested solution of @santo_13 as the official solution since it will introduce electronic components that would require calibration of the voltages read by the DAQ hardware; while the IF2004/USB interface eliminates this requirement. I did, however, give that user Kudos, which is the next best thing, I suppose. I have uploaded a newer version of my LV code with the solution.

LabVIEW

Align DAQmx Data with Data from Non-DAQmx Device

Solved!

Author

If I were to purchase new data acquisition hardware for the purpose of synchronizing our load cell and laser acquisitions, what would be the minimal set of NI equipment you would recommend? I would like to continue using the IF2004/USB interface for the lasers, but have the DAQ device send a trigger to it to start and continue synchronous data acquisition along with the load cell.