Stanford Research Systems SR785, Руководство по эксплуатации и программированию

Страница: 334 / 546

4-138 Waterfall Menu
SR785 Dynamic Signal Analyzer
record increment. (In the case of triggered measurements, skip+1 times the trigger
period). This allows the time between stored records to be determined exactly.
In Octave group, the Storage Interval is set as a time. In this case, a snapshot is stored to
memory every Storage Interval amount of time (4 ms minimum with 4 ms resolution).
The Skip/Storage Interval has a slightly different effect if the measurement is linear
averaged. In this case, the result of every Nth complete linear average is stored in the
waterfall buffer and the average is reset and started over again. Change the Number of
Averages (FFT, et. al.) or Integration Time (Octave) to change the storage rate.
Depending upon the storage rate, the waterfall display may not scroll fast enough to
show every record being saved. In this case, the displays are redrawn with all visible
records shown when the measurement is paused.
Command: WFSK (?) d {, i} or WOSK (?) d {, x}
View Count
Set the Waterfall View Count for the active display [2..2048]. The View Count is the
number of records shown within the display. This number is independent of the Total
Count (number of records stored). The View Count is the Z axis scaling of the waterfall
display and should be less than the Total Count in order to use the display area
effectively.
Setting the View Count to a large number (>40 or so) will cause the display to skip some
records. In this case, every nth record is drawn in order to show the desired View Count
range of the waterfall buffer. A large View Count is a good way to display an overview
of the entire buffer in order to identify a region of interest. Remember, View Count is
strictly a display parameter, it does not affect the actual storage of waterfall records.
The View Count and the Trace Height determine the available scroll Angles.
Each display has its own Waterfall View Count. This entry field can be linked to both
displays by using the [Link] key.
Command: WVCT (?) d {, i}
Angle
Set the requested Waterfall Scroll Angle for the active display.
Waterfall displays show multiple measurement results (records) in a single display. New
records are added at the top of the display and older records scroll off the bottom of the
display. When the Scroll Angle is 0, the older records scroll straight down. When the
Scroll Angle is negative, the older records shift left as they scroll down. When the Scroll
Angle is positive, they shift right as they scroll down.