User manual

Programmer’s Guide Page 57 of 64
While this mode even ‘works’ for nbrSegments = 1, in practice the value of nbrSegments should be at least 3. It is
important to note that after the acquisition of a segment, the digitizer automatically advances to the next memory
section and immediately (with a dead time of ~ 1 μs) starts recording into it. Thus, usually the very last memory
segment used will necessarily contain uninteresting data, since it will not be stopped with a trigger, but be terminated
with the software command AcqrsD1_stopAcquisition.
Use this code to use the ‘Sequence Wrap’ mode:
AcqrsD1_configXXX(.. ); // configure other parameters
AcqrsD1_configMode(instrID, 0, 0, 2);
AcqrsD1_acquire(instrID);
..
AcqrsD1_stopAcquisition(instrID);
The time at which the sequence is terminated with the function AcqrsD1_stopAcquisition depends on an external
event, e.g. operator intervention.
When reading the segments, the segment number should take on the values 0,…(nbrSegments-1). They correspond
to the memory section numbers in the digitizer, not the time order of the acquired segments.
Example: if nbrSegments = 8, the time order of the acquired segments might be (depending on when the sequence
was stopped) 5, 6, 7, 0, 1, 2, 3, 4. Here, the ‘oldest good’ segment is the 5
th
segment, followed by the 6
th
, 7
th
, 8
th
, 1
st
etc. The ‘youngest’ useful segment is the 2
nd
one, while the 3
rd
or 4
th
segment corresponds to the segment that was
being recorded when the stop-command was received. The 4
th
segment (in this example) usually does not contain any
useful data. However, depending on the timing of the triggers with respect to the acquisition stop it could be that the
3
rd
segment has the corrupted data and the 4
th
is valid.
3.18.2. Stream Data (mode 1)
The SC2x0 Streamer Analyzers (U1091ASC1, U1080A-002), and the AC2x0 Signal Analyzers (U1091AAC1,
U1080A-001) support this data streaming mode. Please refer to the specific product manuals for further information:
• Signal Analyzers, User Manual (U1092-90006)
• Streamer Analyzers User Manual (U1092-90007)
3.18.3. Averager (mode 2)
In Averaging mode, newly acquired waveforms are summed in real-time with the corresponding samples of previous
waveforms. The corresponding samples are those with identical delay calculated from the beginning (trigger time) of
the acquisition. This mode is supported by AP235/AP240 (U1082-AVG), AP100/AP200 (U1081A) and U1084A
models only. For further information please refer to the specific user manual:
• Averagers User Manual (U1092-90011)
• MD1 Digitizer User Guide & SFP Help – U1084A Averager section.
3.18.4. Dual Memory (mode 3)
The AP101, AP201 (U1081A) Analyzers support a Dual Memory or Buffered data acquisition mode. The Buffered
Sequence Acquisition mode allows the capture and storage of consecutive “single” waveforms. Sequence
Acquisition mode is useful as it can optimize the digitizer’s sampling rate and memory requirements for applications
where only portions of the signal being analyzed are important. For further information please refer to the specific
product manual:
• Analyzers, User Manual (U1092-90020)
3.18.5. Peak
TDC
(mode 5)
This mode is supported by PeakTDC Analyzer models AP240 (U1082-TDC) and U1084A-TDC model. The peak
detection and analysis mode allows real-time acquisition and peak detection. The mode also enables the creation of a
histogram of peak position vs. time for successive acquisitions, the histogram bins containing peak counts or
summed peak amplitudes. Please refer to the specific product manual for further information:
• Analyzers, User Manual (U1092-90020)
• MD1 Digitizer User Guide & SFP Help – U1084A Peak
TDC
section.