NAU - Team ELDO

Experiences With the Design Process - Lab Work


The second phase of our project was to do lab work so that when the proposal gets approved the next team of students does not have to start their work from step zero. Our goals during this phase are to get the computer-oscilloscope combination working perfectly and use the combination to measure voltage abberations in 120V circuits and do basic analysis on the data.

To get the oscilloscope and computer connection to work as desired we needed to:

  • Have LabView recognize the signal from the oscope
  • Use the oscilloscope to automatically trigger on various events
  • Store triggered data on the computer
This rather basic list of functionalities was suprisingly difficult to achieve.

We have had a hard time getting LabView to even recognize the oscilloscope. After spending hours with tech support, the only version of LabView that we have got to interact with the oscopes provided by the school is a trial version. Using this trial version has been a chore since the software requires internet access and does not save the recieved data to an acceptable resolution. We are currently still working with LabView and Techtronix to see why LabView 10.0 does not work and LabView SignalExpress (Trial Edition) does.

The oscilloscope has functionality built in to automatically trigger on high voltage levels and switching times. Since we are looking at AC signals, some transients will not be caught by a voltage level trigger. To solve this we have built a high pass filter to filter out the main 60Hz component and trigger off of the remainder while saving the original waveform . Currently the data is only stored to two significant figures, which dues not support frequency analysis well. When LabView 8 recognizes the scope this problem will be solved. The data is stored to the hard disk with a time stamp on a triggering event, and so when the truncation problem is solved our task of organizing data storage will be finished. Finally we will make a writeup of how to use the scope/computer combination so that future students working on this project do not have to redo the work we have done.