Problems with some instructions for using USB

[siul82mx]

Hello everybody I have a problem, i am making a  program using LabWindiws 7.1 for a USB control (ty and rx mainly), i have made some tests asking for some details about my usb raw, and it is ok, but for certain commands for example for the attributes VI_ATTR_USB_NUMPIPES,VI_ATTR_USB_BULK_IN, VI_ATTR_USB_BUL_OUT y got the next error when i compile the program

undeclared identifier VI_ATTR_USB_NUMPIPES
 

I don not why, i declared the visa library since the begining (#include <visa.h>   ), i have read this .h file and almost at the end has some instructions that seems to be only available when you declarate NIVISA_USB or something like that because has the next restriction : #if defined(NIVISA_USB)    so how can i include this part of the library, or how i need to declared it...?

Thanks

[markus kossmann]

You have to #define  NIVISA_USB

Either with  :

#define NIVISA_USB

#include <visa.h>

in your source code

or

add \DNIVISA_USB

to the compiler defines field in the Build Options dialog of your workspace

[siul82mx]

Thanks for the helpfull tip, now everything it's ok. Bye