Agilent Technologies Model A.08.xx manual 158

Programming Examples

Determine if an Error has Occurred

/* 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 SRQ Event Occurred!\n");

printf ("\n ... Original Device Session = %1d\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 either a measurement is uncalibrated or an error message has occurred?*/

viQueryf(viESA, "STAT:QUES:INT:EVEN?\n", "%d", &iStatusByte); if ( (0x08 & iStatusByte))

printf("\n SRQ message:\t Measurement uncalibrated\n");

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

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

printf("\n SRQ message:\t Measurement complete\n");

else if ( (iStatusByte !=0) && (0x02 0x10 0x20 & iStatusByte ))

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

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

}

void main()

{

/*Program Variables*/ ViStatus viStatus = 0;

long	lOpc= 0L;
int	iIntNum= 0;
long	lCount= 0L;

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

{

printf("Could not open a session to GPIB device at address 18!\n"); exit(0);

158 Chapter 3