passing booleans to LabView dll

[steve h]

I have created a Labview vi (7.1) that I have converted to a dll which uses a cluster of Booleans as a input. I set Test Stand (2.0) to pass a Structure (1 byte boundary) with Booleans as the data type (Test Stand also asks for a numeric type for some reason); is this the correct method?  I get the message 'no type information in the dll' when loading the dll from Test Stand, is this normal for Structure/Cluster passing?

[SachaE]

Hi Steve,

   the No type information relates to the parameters being passed, so you have to make it up yourself in TestStand to match the setup you've given in LabVIEW when you built the .dll

LabVIEW packages booleans as U8's, so that's why it's asking for a number - there is no BOOL type itself - we address by byte only.

http://digital.ni.com/public.nsf/websearch/DBCE27265FFB554986256C9400026FE8?OpenDocument

This means that booleans are essentially a complex type, however useing U8s instead uses the same amount of space, and if you're not using clusters to simply keep them together, then you'll get prototype information out.

Useful other threads below :

http://forums.ni.com/ni/board/message?board.id=170&message.id=122260&requireLogin=False

http://forums.ni.com/ni/board/message?board.id=330&message.id=6140&requireLogin=False

Hope that helps

Sacha Emery
National Instruments (UK)