I need to acquire impulsive signal(s) and then write them to a file - but I need a good approach

Question

Okay, I am pretty new to Lab View, and would appreciate suggestions of how to approach a problem.
My
only LabView experience has been writing a simple .vi to acquire
voltage signals in a loop at a certain sample rate, get 5 of them each
time the loop iterated (it did so every second), average the 5 samples,
and dump them into a file at every loop iteration.
That
was for continuous data acquisition while viewing/monitoring the data
at the same time, and was probably not the most efficient way (or even a
good way) to do it.
Now,
I am doing something different.  I want to record voltage signals but
only after a trigger event has occured, and only until a certain time
window after the trigger event. 
Should I use continuous data sampling? 
Or should I sample "N" samples?
Should I use "producer / consumer" structure?
Should I continuously log to a TDMS file (I just started reading about that.... I used lvm files before....)?
I
am very confused.  I have enough programming knowledge to be dangerous,
but am very new to Lab View.  Any quick pointers to get me started? 
This is sort of time-critical....
Thanks a lot
-Jay

Answer 1

Jay,
There are quite a few examples in the example finder of how to implement various types of triggers IIRC.
How long is your time window and how fast do you want to sample?  That will probably determine whether you want to use N samples (for shorter time windows where all your samples will fit in the hardware buffer) or continuous (for when you will want to make several reads before you have enough data).
Producer/consumer is a very versatile design pattern.  If you have a long running acquisition that you'd like to be able to cancel or update the UI mid run then you might want to use it.  If, on the other hand you are doing a quick (in UI terms) acquistion then there may not be any need.  Templates and design patterns also become more important the longer you plan to keep the code around -- the more you plan to maintain and add onto the VI the more thought should go into the design.
File format is often a personal preference.  TDMS is a richer file format (faster, smaller, IMO normally better) than LVM (essentially just a text file).  TDMS files can be opened in Excel with a plugin or natively in any NI tools (LabVIEW, DIAdem etc.)  Text files such as LVM can be opened with just about anything.  One thing that may force your decision is if you are acquiring large amounts of data quickly (too fast to buffer in RAM) then you'd definitely want to use TDMS as it is much faster and gives your hard drive a chance to keep up with the inflow of data.
Good luck, let us know how you get on.
~Simon