VISA LOCK/UNLOCK

[Yunhua]

Hi,

I want to ask a visa(or gpib) lock/unlock question,for example:

Fun1()

{

visa_write(visession,command1);    

visa_read(response1);

}

Fun2()

{

visa_write(visession,command2);    

visa_read(response2);

}

Because Fun1 and Fun1 executed in different threading,How to guarantee there is no interrupt between

visa_write(visession,command1);    

visa_read(response1);

or

visa_write(visession,command2);    

visa_read(response2);

???

And if there is a way to LOCK/UNLOCK, if FUNC1 is LOCKED the VISA resource, How Func2 knows when the VISA resource is UNLOCKED?

Thanks for you attention.

==========================================

Using CVI 6.0 PDS on Win XP.

==========================================

[Yunhua]

Hi,

   I aslo have some experience in using LabView,  and kown there are Visa lock and unlock functions, and there is a notify method to do this, but what these functions in CVI?

[RobertoBozzolo]

I'm not familiar vith VISA functions, but you should be able to manage locks between threads by using locking functions included in the multithreading environment provided by CVI: CmtNewLock, CmtGetLock and CmtReleaseLock. These functions are described in the online help and in this document installed with CVI: <cvidir>\bin\multithreadingOverview.pdf

[Yunhua]

Hello Roberto Bozzolo,

     Thanks for your reply.  The functions CmtNewLock, CmtGetLock and CmtReleaseLock are exactly what need. To combine use with viLock, viUnlock, It works perfectly.

  Thanks for NI LabWindows/CVI Discussion Forums again.