topic Re: omitting CAN library in LabWindows/CVI

omitting CAN library

Wolfgang — Wed, 18 Mar 2009 18:20:58 GMT

Hi,

I have a measurement program written in CVI that supports several instruments; communication is via serial, TCP, GPIB, or CAN interfaces.

Now I want the same program to compile (and run) on a computer that has no CAN instrument, and thus no CAN library is installed.

The executable has a configuration option that enables/disables CAN instrument support, so the lack of the instrument doesn't hurt if the switch is set properly.

The idea is that I can work on the program on my notebook as along as I do not need to work on the CAN related functions.

However, I cannot compile the code without the CAN library installed, because function prototypes exist that include constants such as NCTYPE - hence without the library I receive compilation errors.

Thanks for assistance,

Wolfgang

Re: omitting CAN library

Wolfgang — Thu, 19 Mar 2009 16:18:48 GMT

I may add that NI-CAN is not supported on XP64, so there seems to be no possibility to work on my code as soon as I include the CAN library, even if I want to modify CAN-free routines only.

What I am looking for is a possibility to include a 'dummy library' or file that includes all NC-definitions once the CAN is unavailable, or a suitable macro etc. to disable all CAN-related function calls in my source code, permitting the compilation of the code for test purposes without the library.

Is it possible?

Thanks, Wolfgang

Re: omitting CAN library

Mert_A. — Thu, 19 Mar 2009 17:53:30 GMT

Presuming your CAN-related implementation is fairly isolated, one possibility would be to wrap all that code in a preprocessor conditional like #ifndef CAN_NOT_SUPPORTED. When developing on your laptop, you would add CAN_NOT_SUPPORTED to the compiler defines found under Options>>Build Options dialog.

Mert A.

National Instruments

Re: omitting CAN library

Wolfgang — Fri, 20 Mar 2009 07:26:35 GMT

Thanks Mert! The compiler define (/DCAN_NOT_AVAILABLE=1) indeed did solve my problem! I only have to include a line

#ifndef CAN_NOT_AVAILABLE

in the include file of all my CAN functions, and all complaints of the compiler are gone 🙂

And I've got to know the compiler define feature...

Wolfgang