Running subVI in parallel with itself using producer-consumer pattern

Question

I'm using the procuder-consumer pattern to create what I call threads in response to various events much like in Producer Consumer with Event Structure and Queues
I have several physical instruments, and would like to run the exact
same test in parallel on each of the instruments.  I have a subVI
that takes as inputs a VISA resource and a few control references among
other things and then performs the desired experiment.  I have a
separate consumer loop for each physical instrument, with this subVI
inside each consumer loop.
My test VI worked great; each consumer loop was a simple while loop
incrementing a numeric indicator (not using my real subVI above). 
However, my real program can only run one consumer loop at a time much
to my dismay.  Reworking my simple test VI to use a subVI to
increment the indicator rather than just explicitly coding everything
resulted in the same problem: only a single consumer loop ran at a time
(and as I stopped the running loop, another would get a chance to
begin). The subVI in this case was extremely
simple taking only a ref to the indicator and a ref to a boolean to
stop, and incrementing the indicator in a while-loop.
Is there a way around this?  Now that I've spent the time making a
nice subVI to do the entire experiment on on the physical instrument, I
thought it would be fairly trivial to extend this to control multiple
instruments performing the same experiment in parallel.  It seems
only one instance of a given subVI may run at one time.  Is this
true?  If it is indeed true, what other options do I have?  I
have little desire to recode my subVI to manually handle multiple
physical instruments; this would also result in a loss of functionality
as all parallel experiments would run more or less in lock step without
much more complexity.
Thank you.

Answer 1

You need to make your subvi reentrant.  Then it can run several instances at any time with each instance occupying its own unique memory space.  Click on File - VI Properties - Execution, and check the reentry execution checkbox.  Then save the vi.
- tbob
Inventor of the WORM Global