Passing string to DLL from Labview

[Vincenzo Varoli Member Find all posts View Profile Close Vincenzo Varoli]

I am writing a dll that contains a few sub to control an instrument from Labview.
I succeed in passing numerics parameters but I did succeed in passing strings (dynamic strings).
I tried almost all the options in the Labview dialog but I got always errors.
How can I pass a string?
Thanks in advance and best regards.
Vincenzo Varoli

[Michael Mattias Member Find all posts View Profile Close Michael Mattias]

Without the Labview doc, I can't be sure, but I'll bet ninety percent of 'string' parameters to third-party library calls use a "C" style null-terminated string... ASCIIZ in Pb-Speak....not an "AS STRING" type

If the 'c' declaration for the function shows "*char" as the parameter, then that's an ASCIIZ string.

Try this . if that does not work, post the doc/declare for the Labview function and someone here will be able to help. It will also help to show the relevant portions of your calling code.

(If changing to ASCIIZ does work, advise here, too.)

MCM

[Vincenzo Varoli Member Find all posts View Profile Close Vincenzo Varoli]

Many thanks.
I solved the problem using fixed length strings (declaration AS STRING*n ).
It seems that Labview does not accept dynamic strings.
I shall test also ASCIIZ strings.
Regards
Varoli