Programming instructions

VISA Programming Examples How to Co-ordinate Two Modules
200 Agilent 8163A/B, 8164A/B & 8166A/B Mainframes, Fifth Edition
errStatus = viOpen (defaultRM, "GPIB::20::INSTR",
VI_NULL,VI_NULL,&vi);
if(errStatus < VI_SUCCESS)
{
printf("Failed to open instrument\n");
exit(errStatus);
}
/* set timeout to 20 sec; this should work for all commands except
zeroing */
errStatus = viSetAttribute(vi,VI_ATTR_TMO_VALUE,20000);
if (errStatus < VI_SUCCESS) checkError(vi,errStatus);
/* clear error queue */
errStatus = viPrintf(vi,"*CLS\n");
checkError(vi,errStatus);
/* read the wavelength from the laser source */
errStatus = viQueryf(vi,"SOURCE2:CHAN1:WAV?\n","%s",replyBuf);
checkError(vi,errStatus);
/* feed the source wavelength into the power meter making
sure to measure the maximum power of the source */
errStatus = viPrintf(vi,"SENS1:CHAN1:POW:WAV %s\n",replyBuf);
checkError(vi,errStatus);
/* turn auto range on */
errStatus = viPrintf(vi,"SENS1:CHAN1:POW:RANGE:AUTO 1\n");
checkError(vi,errStatus);
/* change the power unit of the power meter to dBm */
errStatus = viPrintf(vi,"SENS1:CHAN1:POW:UNIT 0\n");
checkError(vi,errStatus);
/*set the averaging time for measuring to 20 ms,
therefore no timeout needs to implemented */
errStatus = viPrintf(vi,"SENS1:CHAN1:POW:ATIME 0.02\n");
checkError(vi,errStatus);
/* set the attenuation to zero for maximum power */
errStatus = viPrintf(vi,"SOURCE2:CHAN1:POW:ATT 0.0\n");
checkError(vi,errStatus);
/* set the reference mode to the internal one,
which is now the last displayed value */