Ibnotify callback doesn't trigger

[Lex_312]

Hi,

I'm trying to get an ibnotify callback system working. At the moment I'm just trying to develop an example program to emulate an instrument's GPIB interface. The example program (interrupt_test.cpp) is running on a windows XP system, with NI VISA 5.0. I'm building all my code in Visual Studio 2008. The system controller is an older machine running NI-488.2 version 1.70.

Because I'm trying to do instrument emulation, I set up the GPIB interface as a non-system controller as follows:

//initialize GPIB bus

noncontroller = ibfind("gpib0");

//release system control

ibrsc(noncontroller,0);

//change the primary address

ibpad(noncontroller,2);

I set up ibnotify as follows:

ibnotify(noncontroller, gpibMask, gpibCB, NULL);

with gpibMask = (LACS|TACS|DCAS|CMPL);

My Callback is then defined as 

int __stdcall gpibCB(int ud, int localIbsta, int localIberr, long localIbcntl, void *refData)

The problem is that the callback never triggers. If I set my original mask to only LACS - it will trigger, but it won't re-trigger for the next case (when I want to say, be addressed as a talker).

I'm attaching the example code I've written, and I'm really hoping someone can help me find the problem here - I know there must be something obvious I'm missing.

Thank you,

Lex

[Lex_312]

Ok I have the callback triggering - 

I accomplished this by using a global variable for the mask that is shared between the main program and the callback thread.

The problem now, is that I never hit my I/O complete state (if (localIbsta  & CMPL)) in the callback.

After a write to my program (listener state) I set my mask to (TACS|DCAS|CMPL)

Again - any ideas?

Thanks,

Lex

[Lex_312]

Ok - Sheepish grin - 

It appears I've figured it out - I was missing a critical case statement in the read state - 

resetting the system to the idle state and removing the i/o complete mask was important, if there was nothing on the output buffer 🙂

           currentIo = idleState;         

            gpibMask = (DCAS | LACS);

Thanks again, 

I think I'm all set

Lex