Agilent Technologies Model A.08.xx manual 152

Programming Examples

Status Register–Determine When a Measurement is Done

/* Make sure it is an SRQ event, ignore if stray event*/ if (eventType!=VI_EVENT_SERVICE_REQ)

{

printf ("\n Stray event type0x%1x\n",eventType);

/*Return successfully*/ return VI_SUCCESS;

}

/* When an interrupt occurs,determine which device generated the interrupt (if an instrument other than the ESA generates the interrupt, simply report "Instrument at GPIB Address xxx Has Generated an Interrupt").*/

printf ("\n\n SRQ event occurred!\n");

printf ("\n ... Original Device Session = %t\n",viESA);

/*Get the GPIB address of the insrument, which has interrupted*/ viQueryf(viESA,"SYST:COMM:GPIB:SELF:ADDR?\n","%t", cBuf);

printf ("\n Instrument at GPIB address %s has generated an interrupt!\n",cBuf);

/*Get the status byte*/

/* If the ESA generated the interrupt, determine the nature of the interrupt; did the measurement complete or an error message occur?*/

viQueryf(viESA, "*ESR?\n", "%d", &iStatusByte); if ( (0x01 & iStatusByte))

printf("\n SRQ message:\t Measurement complete\n"); else if ( (0x02 0x10 0x20 & iStatusByte ))

printf ("\n SRQ message:\t Error Message Occurred\n");

/*Return successfully*/ iSrqOccurred =1; viReadSTB(viESA,&iStatusByte); return VI_SUCCESS;

}

/* Main Program*/ void main()

{

/*Program Variables*/ ViStatus viStatus = 0; long lOpc=0;

/* Open a GPIB session at address 18*/ viStatus=viOpenDefaultRM(&defaultRM); int address =18; viStatus=viOpen(defaultRM,"GPIB0::18",VI_NULL,VI_NULL,&viESA); if(viStatus)

{

152 Chapter 3