Need to record data for 4 hrs at a rate of every 30s

Question

Hello,
I'm fairly new to LabVIEW and need assistance. I have this VI that manually records torque and temperature by hitting a button. I want to alter it so that when I run the program  I can automatically collect data every 30 sec for 4 hrs and then the program stops. Any help would be appreciated. I have attached the VI. 

Answer 1

Bob_Schor wrote:
One of the most difficult things for people new to LabVIEW to avoid is the temptation to "just start coding" -- as often as not, you end up with a bunch of (often Express) VIs wired together that do something, but rarely what you want it to do.
I recommend starting with thinking about the overall design, asking yourself "What do I want to do?".  In your case, it sounds like "Record data (not yet defined) every 30 seconds for 4 hours".  Now break this down -- what does "record data" mean?  How much data?  How many channels?  What data rate?  What do you want to do with the data?
This might be a "unit" of your code, that is, this "Data Recording Block" might, in some ways, stand alone.  One way this could happen would be if you recorded, say, 5 seconds of data, wrote the data to a uniquely-named file, then stopped recording.  "Aha!", I (don't) hear you saying, "this should be written as a sub-VI called "Save Some Data" that I put in my main program and call every 30 seconds until 4 hours have gone by".
What is this isn't your model?  Maybe you want to start data acquisition, keep it running, and every 30 seconds save some aliquot of the data to a file.  Fine, but that's another Design Decision that you should make before starting to code.  This kind of model sounds liek it might be a Producer (continuous data acquisition)/Consumer (periodic saving of the data) design, with the Consumer "worrying" about saving, say, 5 second aliquots of data every 30 seconds for 4 hours.  This last bit (namely getting the Consumer to "do its thing" properly) might be handled by a State Machine design ("Save to File", "Wait for next Sample Time", "Count Elapsed Time").
Here is a piece of Good Advice -- never put an "Abort LabVIEW" command in your program!  Notice you have a Stop button to stop the loop, and can OR wire the output now going to the Abort to the same Stop indicator.  Use Abort in the rare instance where failure to instantly kill the program will result in someone's death or injury -- you're not yet ready to code at this level.
Bob Schor
To expand on this idea, I usually write up at least a "casual" requirements document - even if it's just a few paragraphs - and code each "requirement" as a subVI.