Labview 2012 and DDE

[n_led]

Hello, 

I found this thread and thought that if someine needs a dde.dll in 2012 LV version he may stick to the same problem with the code interface node that I am trying to solve, so I will just put a link to my post here. 

http://forums.ni.com/t5/Digital-I-O/Code-interface-node-in-DDE-master-control-vi-in-LabView-2013/td-...

thanks for help

[n_wint]

Sorry if this sounds like a strange question but I came across this thread as I am trying to use DDE in a project I have. My question is, why is the DDE llb not included in the 64bit version of the software?

Is DDE supported in 64bit windows?

Thanks

Nathan

[ChrisStrykesAgain]

DDE is not supported in 64-bit LabVIEW editions. This is because all .dll's being called must match the "bitness" of the calling application. Unfortunately, the underlying Microsoft .dll is 32-bit.

Because of some emulation protocols that happen with the windows OS, however, you are able to run the 32-bit version of LabVIEW and make calls to DDE. You are also able to install 32-bit and 64-bit instances of LabVIEW simultaneously, but they are not inter-operable.

[banksey255]

I know this is an extremely old topic, but based on the rationale that it is easier to find if everything is kept together, I needed to use DDE to interface with some hardware (a Quizix pump), but wanted to use LabVIEW 64-bit, so I developed a vi to do it, which I'm uploading in case it saves others some time.

As far as I can tell, for that which I've implemented, it is near identical to how dde.lib that is bundled with LabVIEW 32-bit operates. I didn't replicate all the functionality of dde.lib as I didn't need it in my application, yet perhaps, if nothing else, it will still act as a useful starting point. I developed the vi in LabVIEW 2019, it just demonstrates how to achieve certain functionalities, and, in principle, should also work with LabVIEW 32-bit (albeit probably I'd just use dde.lib bundled with LabVIEW 32-bit in that case).

[banksey255]

I've attached an updated vi that adds a proof-of-concept of the execute transaction and fixes a few issues I discovered. At this point it seems that to get any additional functionality that is also part of LabVIEW 32-bit's dde.lib would require a callback function, which LabVIEW doesn't support.

[CFRandall]

Banksey, 

Thank you so very much for sharing this! You've saved us days (or weeks?) of work, and, quite possibly, the cost of replacement equipment down the line. 

C. R.