Hi, I'm a graduate student at Tufts University. We are building an experimental apparatus with data acquisition all together.
I wrote a VI that reads from 16 Analog input channels and a digital input channel. It also writes to 1 analog output channel and a digital counter channel. I synchronized the tasks with a sample clock which has a rate set to 10000. Since I needed to log all 16 Analog input as well as the one digital, I converted the digital waveform into analog waveform and then built an array from there. This array was then inserted into the 1-D array of analogy waveforms(from my 16 ai). I logged this combined array into a txt file using "Export Waveforms to Spreadsheet File". Now here is my problem:
The digital data occasionally do not line up with the analog waveform array in time, causing unpredictable data gaps (see attached txt sample data file). I discussed this problem with a few colleagues of mine but nobody could make out of anything. We even suspected that maybe it has something to do with the processing power. Please help!!! We were just about to proceed with our experiments when this bug caught our attention.
My NI device is PXI-6229, and my LabView version is 8.0