How to Co-ordinate Two Modules VISA Programming Examples
Agilent 8163A/B, 8164A/B & 8166A/B Mainframes, Fifth Edition 199
How to Co-ordinate Two 
Modules
This example shows the interaction of two modules in the same frame.
Install a Power Sensor in Slot 1 and a Laser Source in Slot 2 and connect 
the 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 */ 
  ViInt32       i;             /* loop counter */
  ViInt32       cmdDone;       /* return value for OPC command */
 
    /* First get initialized the visa library (see example 1) */
    errStatus = viOpenDefaultRM (&defaultRM);
    if(errStatus < VI_SUCCESS)
      {
        printf("Failed to open VISA Resource manager\n"); 
        exit(errStatus); 
      }
    /* Open session to GPIB device at address 20; */