/* srqhdlr.c
This example program illustrates installing an event handler to
be called when an SRQ interrupt occurs. Note that you must
change the address. */
#include <visa.h>
#include <stdio.h>
#if defined (_WIN32)
#include <windows.h> /* for Sleep() */
#define YIELD Sleep( 10 )
#elif defined (_WINDOWS)
#include <io.h> /* for _wyield */
#define YIELD _wyield()
#else
#include <unistd.h>
#define YIELD sleep (1)
#endif
int srqOccurred;
/* trigger event handler */
ViStatus _VI_FUNCH mySrqHdlr(ViSession vi, ViEventType eventType,
ViEvent ctx, ViAddr userHdlr){
ViUInt16 statusByte;
/* make sure it is an SRQ event */
if(eventType!=VI_EVENT_SERVICE_REQ){ /* Stray event, so ignore */
printf( "\nStray event of type 0x%lx\n", eventType );
return VI_SUCCESS;
}
/* print the event information */
printf("\nSRQ Event Occurred!\n"); printf("...Original Device Session = %ld\n", vi);
/* get the status byte */
viReadSTB(vi, &statusByte);
printf("...Status byte is 0x%x\n", statusByte);
srqOccurred = 1;
return VI_SUCCESS;
}
void main(){ ViSession defaultRM,vi;
long count;
/* open session to message based VXI device */
viOpenDefaultRM(&defaultRM);
viOpen(defaultRM, "GPIB0::24::INSTR", VI_NULL, VI_NULL, &vi);
/* Enable command error events */
viPrintf( vi, "*ESE 32\n" );
/* Enable event register interrupts */
viPrintf( vi, "*SRE 32\n" );
/* install the handler and enable it */
viInstallHandler(vi, VI_EVENT_SERVICE_REQ, mySrqHdlr, (ViAddr)10);
viEnableEvent(vi, VI_EVENT_SERVICE_REQ, VI_HNDLR, VI_NULL);
srqOccurred = 0;
/* Send a bogus command to the message based device to cause an SRQ */
/* Note: 'IDN' causes the error -- '*IDN?' is the correct syntax */
viPrintf( vi, "IDN\n" );
/* Wait a while for the SRQ to be generated and for the handler */
/* to be called. Print something while we wait */
printf( "Waiting for an SRQ to be generated ." );
for ( count = 0 ; (count < 10) && (srqOccurred == 0) ; count++ ) { long count2 = 0;
printf( "." );
while ( (count2++ < 100) && (srqOccurred ==0) ){ YIELD;
}
}
printf( "\n" );
/* disable and uninstall the handler */
viDisableEvent(vi, VI_EVENT_SERVICE_REQ, VI_HNDLR);
viUninstallHandler(vi, VI_EVENT_SERVICE_REQ, mySrqHdlr, (ViAddr)10);
/* Clean up after ourselves - don't leave device in error state */
viPrintf( vi, "*CLS\n" );
/* close the sessions */
viClose(vi);
viClose(defaultRM);
printf( "End of program\n" );
}