Hello,
Depending on how the DLL is expecting to receive the buffers from the
calling application, we may have to do different things in LabVIEW to
get it to work. Often a DLL will expect an pointer to an array (aka a
buffer), generate data and update the array, then pass the pointer to
the array back out for use in the calling application. If this is the
case, we can define and allocate an array in LabVIEW of the correct
data type, configure the Call Library Function Node to accept an array
as an input, and wire the two together.
From the VI's you attached, it will be tough to tell you how to do it,
since we don't have the DLL to look at (or it's header file, which
would tell us what data types it expects). You will need to find the
documentation for the DLL you which to use. A very handy reference is
the example program Call DLL.vi, which ships with LabVIEW. This VI
gives LabVIEW code examples for calling DLL's with numerous data types,
including arrays. This will show you how to configure your application
for the data type the DLL expects. Give this a look and you may find
what you're looking for!
Cheers,
Matt Pollock
National Instruments
