How do I access the functions of a 32b DLL from LV 64b?

[Marinica]

Hello,

I have a simple 32b DLL file without a header. From LV-32b I could reach it well. If I run the same VI, but from LV-64b, generates error 12.
Is there a way to access the 32b DLL from LV-64b?

Thanks.

[billko · Accepted solution]

Nope.  Read the first sentence of paragraph 2 here.  It's not related to LabVIEW.  This is just Windows doing its thing.

Any reason why you want to run LV 64-bit?  There's a host of reasons why you wouldn't want to, and only one reason why you would...

[Marinica]

Thanks,

By the way, which would be the only one reason to run the 64b version?:)

Best Regards.

[Norbert_B]

Huge data sets.

32bit process running on a 64bit OS are limited to 4GB of memory. This memory is provided in blocks, so fragmentation takes place.

So copying large data sets can easily run you out of memory.

Norbert

[Marinica]

So, using a large array of data structures can may not have memory space. Do you know what would be the limit (a data block size)?
Are there no other differences related to the execution speed or calculation speed?

BR

[Norbert_B]

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@Marinica wrote:

So, using a large array of data structures can may not have memory space. Do you know what would be the limit (a data block size)?
Are there no other differences related to the execution speed or calculation speed?

BR

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There is not "the limit". It depends on previous fragmentation and number of copies. You can use the VMMap tool from Microsoft (previously SysInternals) to review OS process memory usage.

There shouldn't be a (huge) difference. However, i am not sure because "address space" (which OS bitness refers to) is different to numeric width of the CPU. So ideally, there is 0 difference....

Norbert

[NIquist · Accepted solution]

http://digital.ni.com/public.nsf/allkb/71E9408E6DEAD76C8625760B006B6F98

Another issue with 64-bit is that not all of the available toolkits and addons can work with it yet.  Unless you're analyzing massively large files (genetic, astronomical, statistical, social media-cal , etc. ) you're better off with 32-bit LabVIEW for now.

[billko]

LOL if you are working with HUGE datasets that might push you very near to, or beyond, the 4GB memory limit.  With LabVIEW, it can happen quite quickly and rudely if you are using big datasets and poor memory management.

The biggest reasoon why you don't really want to use LV 64-bit unless you have to is because a lot of tool kits are incompatible.  You've already found the other major reason.  😉

Edit:

I see I was not very quick on the draw.  😉