Stanford Research Systems SR780, Operating Manual And Programming Reference

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Disk Buffers Menu 4-159
SR785 Dynamic Signal Analyzer
of Ch1+Ch2 capture, loading one channel does not disturb the contents of the other
channel’s buffer.
If either the length or sampling rate is different from the current [Capture] menu, they are
changed to the length and sampling rate of the disk data. In the case of Ch1+Ch2 capture,
loading Ch1 (Ch2) capture will zero the Ch2 (Ch1) capture buffer if the capture length or
sampling rate is changed by this operation.
To recall both capture channels, configure <Capture Channels> for Ch1+Ch2. Both files
must contain the same length buffers with the same sampling rate. Use <Buffer> to
choose either Ch1 or Ch2 and load the appropriate disk file to the buffer. This will set the
capture length and sampling rate according to the recalled disk file. Then use <Buffer> to
choose the other channel and load the other disk file to the buffer. Since the existing
Capture Length and Sampling Rate are already compatible, this operation does not zero
the first capture buffer.
Load the Waterfall Buffer
A saved Waterfall file may be loaded into the Waterfall buffer.
Loading a Waterfall file loads data into the waterfall buffer and recalls the measurement
parameters which were in effect when the waterfall buffer was saved. The recalled
parameters include items in the [Frequency], [Display Setup], [Display Options],
[Average], [Window], [User Math], and [Waterfall] menus.
If the file contains records from both displays, data is recalled for both displays. The
Waterfall Storage is set to Recalled. Recalled simply means that the waterfall displays
contain data which did not come from the two inputs but rather from disk.
Recalled waterfall data is not protected in any way! The recalled waterfall data behaves
as if the measurement was paused. Pressing [Start/Reset] or changing any measurement
parameter which normally causes the waterfall buffer to reset and take new data will
destroy the recalled data! The recalled data is available for viewing and hardcopy only.
Command: APUT ? i
Command: CPUT ? i, j
Command: WPUT ?
Command: TPUT ? i
Buffer to Disk
Save binary data from the selected data buffer to the Current File in the Current
Directory. Use <Interval> to select the playback portion or entire buffer.
File Size
All data points are stored in binary as 4-byte IEEE floats. To estimate the disk space
required to save a buffer, compute the number of data points and multiply by 4 bytes. In
addition, there is a small header containing measurement data.
Capture and Arbitrary Waveform are both inherently real data (baseband). Thus the
number of data points in the buffer is simply the length of the buffer in points (or the