Stanford Research Systems SR780, Operating Manual And Programming Reference

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Example Program 5-119
SR780 Network Signal Analyzer
//stb is serial poll byte
char stb;
do {spoll(sr780,&stb,&status);} while (!(stb&128));
//IFC
if (stb&32) {
// If ESB bit set,
// there must be a command error in the Standard Event status word.
// Handle command errors here.
TxGpib (sr780, "*ESR?"); //clear the Standard Event status word
GetGpib (sr780);
printf ("\nEXE error\n");
GetSpace ();
}
}
/* ******************************************************************** */
void GetSr780 (char *getcmd)
// query the sr780 for an answer
// getcmd is the query command string
{
TxSr780 (getcmd); //send query command
GetGpib (sr780); //get response into global recv string
}
/* ******************************************************************** */
void WaitAvg (void)
{
// routine to start a linear avg and wait until both displays are done
int result, avgdone;
avgdone=0;
//init avgdone status
GetSr780 ("DSPS?"); //clear sticky bits in Display status word first
TxSr780 ("STRT"); //start lin average measurement
do {
GetSr780 ("DSPS?"); result=atoi(recv); //read display status word
avgdone = avgdone | (result & 0x0202);
//Check for AVGA and AVGB status bits until both have occurred.
//Remember, they may not be set together in the same query!
//Do not check for both in the same query!
}
while ((avgdone&0x0202)!=0x0202); // both AVGA and AVGB have occurred
}
/* ******************************************************************** */
double GetData (int disp, int bin)
{
//routine to move the display marker to a bin and return the data value
//move the marker in display disp to bin
sprintf (cmd,"MBIN %d,%d",disp,bin);
TxSr780 (cmd);
sprintf (cmd,"DSPY? %d,%d",disp,bin);
//read the data value at bin
GetSr780 (cmd);
return (atof(recv)); //return the value as a double
}
/* ******************************************************************** */
void GetSpace (void) /* Wait for space key */