How Power Varies with Wavelength VISA Programming Examples
Agilent 8163A/B, 8164A/B & 8166A/B Mainframes, Fifth Edition 203
How Power Varies with 
Wavelength
This example shows how the measured power depends on wavelength.
Install a Power Sensor in Slot 1 and a Tunable Laser Source in Slot 2 and 
connect the Tunable Laser Source output to the Power Sensor input, 
before executing this example. 
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <visa.h>
/* function prototypes for this examples*/
/* function for a simple error handling explained in example 1 */
void checkError(ViSession session, ViStatus err_status );
void main (void)
  {
  ViStatus      errStatus;     /* returned error code from visa call */
  ViSession     defaultRM;     /* default visa resource manager 
variable*/
  ViSession     vi;            /* current session handle */
  ViChar        replyBuf[256]; /*buffer holding answers of the 
instrument */
  ViChar        c;             /* used in the keyboard wait loop */ 
  ViReal64      wavelength;    /* used to hold the wavelength of the 
tunable laser source */ 
  ViReal64  wavelength_max;    /*used to hold the maximum 
wavelength of the tunable laser source*/ 
  ViInt32       i;             /* loop counter */
  ViInt32       cmdDone;       /* return value for OPC command */
    errStatus = viOpenDefaultRM (&defaultRM);
    if(errStatus < VI_SUCCESS)
      {
        printf("Failed to open VISA Resource manager\n"); 
        exit(errStatus); 
      }