Programming instructions
How to Measure Power using FETCh and READ VISA Programming Examples
Agilent 8163A/B, 8164A/B & 8166A/B Mainframes, Fifth Edition 195
How to Measure Power using 
FETCh and READ
The example shows the difference between a "FETCh" and a "READ" 
command. 
Install a power meter in Slot 1, 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 compBuf[256]; /* buffer used for comparsion */
 ViChar c; /* used in the keyboard wait loop */
 ViReal64 averagingTime; /* averaging time */
 ViInt32 i; /* loop counter */
 errStatus = viOpenDefaultRM (&defaultRM);
 if(errStatus < VI_SUCCESS)
 {
 printf("Failed to open VISA Resource manager\n");
 exit(errStatus);
 }
 errStatus = viOpen (defaultRM, "GPIB::20::INSTR", 
VI_NULL,VI_NULL,&vi);
 if(errStatus < VI_SUCCESS)
 {
 printf("Failed to open instrument\n");
 exit(errStatus);










