Agilent Technologies DP111 - Manual (Page 42)

User Manual: Agilent Acqiris 8-bit Digitizers Page 42 of 59
where the data is located, select the output format and click OK.
All binary data files found in the source directory will be converted to the desired format. If you are writing
amplitudes with multiple segments, formatting with segments in columns is limited to 200 segments.
4.6. Calibrate
The Calibrate item in the Options menu leads to a sub-menu where a particular type of calibration can be invoked. In
order to use this item the acquisition must be stopped; otherwise the Calibrate option is not selectable. The
possibilities are
ƒ Calibrate instruments - to perform a self-calibration on the digitizers, calibrating the gain, offset, trigger
level and the timing. Performing a calibration compensates for any drift in these properties, typically due to
component temperature variations.
ƒ Calibrate current combine configuration – to perform a calibration only at the current configuration in each
instrument.
ƒ Calibrate External Clock Timing – to do a calibration of the internal TDC in the Continuous External Clock
mode.
4.7. Combine channels
The Combine Channels function in the Options menu gives the
DC135/DC140/DC241/DC241A/DC271/DC271A/DC271AR/DP235/DP240/ U1071A-FAMILY user the control of
how many converters will be used for each channel. This allows the memory size and the sampling rate to be
increased in situations where not all of the input channels need to be acquired. Normally digitizer modules work with
one converter/channel. If two or more converters/channel are desired, the identities of the channels to be used have to
be chosen with the Active Channel control.
4.8. External 10 MHz Reference and External Clock
Either one of the External 10 MHz Reference or External Clock options can be selected in the Options Menu. The
external input threshold option, available in the options menu, must also be set appropriately. The 10 MHz Reference
can be activated at the I/O B output.
The External Clock function is available in AcqirisLive only when using the control panel in Transient Recorder
Mode. The input frequency should be keyed into the clock frequency selector (outlined in red) on the control panel.
Then the appropriate sampling frequency must be selected in order for the proper timebase to be displayed on the
waveform display window. The time window displayed can be manipulated by allocating more or less memory to the
acquisition.
The External 10 MHz Reference in AcqirisLive is designed to work either in Oscilloscope Mode or in Transient
Recorder Mode. The timebase and sample rate for waveform capture is fully selectable when using the external
reference, just as it is when using the digitizer’s own internal reference clock.
4.9. Very Long Memory Autostore
This mode is only available for use when the waveform to be stored requires more space than currently available in
the AcqirisLive waveform buffers. Each waveform will generate 2 readable descriptive files (…_metadata.txt,
…_timing.txt) and more than one binary data files (…aqData16 or …aqData8). The size of the waveform buffer can
be controlled with the -b command line option. The first segment and the first sample to read out can be specified.
Note that if the buffer is large enough for at least 1 full segment, only full segments will be read (i.e. first sample
control is ignored). When saving data to file, you will be prompted for a maximum number of segments per file.
4.10. Additional Waveform Information
The Options menu also includes possibilities to obtain additional information about
the waveform. In both cases described below the display will be updated after each
acquisition.
The “Show Segment Timestamps” option shows a display like the one below:
It gives you the information needed to better understand the trigger times of the
individual segments of an acquisition. By definition the first trigger of an
acquisition occurs at t
1
=0.0. There are two columns for each digitizer. For the n’th