call a text file from Labview program

[Darren]

Read the help for the System Exec.vi...there's an input called "wait until completion" that defaults to True...you must specify a value of False for this input if you want your VI to continue executing after it runs System Exec.vi.

Oh, and Stacked Sequence Structures are bad...very bad.  😉

-D

[bjbdts]

Thanks, Darren, It works!

And I thought stacked sequence structure is good, how come you think it's bad? cuz I see people use sequence structure to get time data for xy graph, to save data... things like that, but again I am new in LV, my thought may be wrong.

bj

[Darren]

Stacked Sequence Structures hide code for no good reason.  Most operations in LabVIEW can happen in parallel, such that sequencing is not needed.  If you do need to force the dataflow in your code, you should string together your functions and subVIs with an error cluster.  And if you are doing things that make this method not possible (like writing to local variables, which don't have error terminals), you should use a Flat Sequence Structure...at least in this case, you can view the code from all your frames at the same time.  The Flat Sequence Structure is only available in LabVIEW 7.0 and later.

If you're still not convinced, post a sample VI showing your use of a Stacked Sequence Structure and I'll tell you how you could do without it.  🙂

-D

[bjbdts]

I totally agree with your comparing stacked and flat sequence structure. I think stacked sequence structure only makes the block diagram more compact.

My vi records temperature and pressure data vs. time. So my x axis is time array, and y axis are temperature and pressure (two xy graphs). To determine the time, I need to set a "start time" at the begining of the program using" tick count" as a base time, so when I continue collecting temperature and pressure data, I use another "tick count" to substract the former "tick count" (its local variable) to get the real time. That's how I use the sequence structure 

bj

[Darren]

  I assume you're using a loop to acquire the data.  Why not use a Tick Count outside the loop, then do the other Tick Count inside the loop to subtract the values?  That way you don't need the Sequence Structure...

Of course, maybe I'm not fully understanding your app.  If my answer didn't make sense, why don't you attach your VI, or a simple VI that mimics your main VI's design, and we can discuss the best way to organize it...who knows, maybe you do require a Sequence Structure...

-D

Message Edited by Darren on 02-24-2006 04:14 PM

[bjbdts]

OK, at this point I agree with you that I can eliminate the sequence structure in my program. I used the sequence structure to input sample rate.

bj