Hey guys, I'm new to LabVIEW and have been working on a task for a while now. I'm trying to measure velocity with my encoder at a sample rate of 1 kHz. I came across some code that calculates velocity using angular position, but due to the sample rate, I couldn't get it to work. So, I started exploring frequency acquisition and thought buffered measurement might be a good option.
My motor runs at around 1800 RPM, and my encoder has a resolution of 1024 pulses per revolution. This led me to estimate a frequency of around 30 kHz. I began using the Low Frequency method with 1 counter, where I generate a clock with another counter of my DAQ and connect it to the gate of the counter that is also connected to channel A of my encoder.
However, for my application, I need to generate a txt file with frequency information and a column for the time of acquisition of each sample. When I perform the frequency measurement, I use the block "DAQ Read" with the option "Counter 1D DBL NChan NSamp," which doesn't provide time information. To address this, I used the "Build WFM" block, set the start time to zero, and dt=1 ms. It kind of works, but not really. I'm generating the x-values for my graph, but I need to be sure that the timestamp is 1 ms because I'll have to match these values with other measurements later.
To verify this, I tried measuring the final time of the waveform and calculating if the rate matches 1 kHz based on the number of samples. However, I noticed that the x-axis values are related to the number of samples. The final time of the simulation is the total number of samples I set for one loop, and also, every time this number is reached, the "time" that I generate resets in the txt file.
Can someone help me understand what I'm doing wrong or suggest an easier way to achieve what I'm attempting? I'm using the NI USB-6341 DAQ. Thanks for the help,
Flavia.
