Data Output Manual
Data Recording System
Data during a cooldown is recorded using a series of LabView modules run persistently on the central DAQ computer in Demeritt 103. General use of this module is beyond the scope of this particular chapter, which is instead intended to explain how to verify that data is being properly recorded during a cooldown and check this output for online and offline analysis.
Throughout the span of the primary LabView program, any variable of general interest to the group is combined with a variable name and appropriate unit and send to a SubVI whose only function is to save the data. While the main program is running, this SubVI should always be visible on one of the screens as a red square with a large green light and a box containing the time of the last recorded data point. If you cannot locate the SubVI, stop the main program with the shortcut CTRL+. and then restart it by pressing the white arrow on the toolbar near the upper left of the program. If the red VI is not visible, it is quite likely data is not being saved. Contact David Ruth or another LabView expert for help resolving this problem.
Once you have found the red VI, you can check it quickly throughout the duration of your shift to determine that data is properly saving. The large green light is known as the heartbeat, and should change from off to on or vice versa every 20 seconds. The light changing state indicates that the program has just saved a data point in the main data output. Further, the box below contains the date and time of the last saved data point. If everything is running correctly, any time you check, the date and time in the box should be within the last 20 seconds. If it is not, some data has been skipped, and it is necessary to immediately resolve the problem before trying to record more important cooldown data. If the light is not flashing, or the output box contains a time further in the past than a minute or so, shift workers should check the output file as detailed in the next session to see where the problem began.
Throughout the shift it is a good idea to visually confirm that the red VI contains the appropriate information every so often, especially before attempting to record any critical data!
