How To Use Visa Calls - Agilent Technologies 8163A Programming Manual

VISA Programming Examples
190

How to Use VISA Calls

The following example demonstrates how to communicate using VISA
calls. Also, the use of instrument identification commands is
demonstrated.
#include <stdio.h>
#include <stdlib.h>
#include <visa.h>
/* This function checks and displays errors, using the error query of
the instrument;
Call this function after every command to make sure your commands
are correct */
void checkError(ViSession session, ViStatus err_status )
{
ViStatus error;
ViChar errMsg[256];
/* queries what kind of error occurred */
error = viQueryf(session,"%s\n","%t","SYST:ERR?",errMsg);
/*if this command times out, a system error is probable;
check the GPIB bus communication */
if (error == VI_ERROR_TMO)
{
printf("System Error!\n") ;
exit(1);
}
else
{
/* display the error number and the error message */
if(errMsg[0] != '+')
printf("error:%ld - - > %s\n", err_status,errMsg) ;
}
}
void main (void)
{
ViStatus errStatus;
ViSession defaultRM;
ViSession vi;
ViChar replyBuf[256]; /*buffer holding answers from the
instrument*/
ViChar c;
Agilent 8163A/B, 8164A/B & 8166A/B Mainframes, Fifth Edition

How to Use VISA Calls

/*return error code from visa call */
/*default visa resource manager variable*/
/*current session handle */