Teledyne SP Devices ADQ14, User Manual

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Classification Revision
Public PA1
Document ID Print date
18-2074 2018-04-06
4.10 Padding
The data padding functionality is used to keep a constant data rate from the digitizer. The padding is
active in the data collection modes pulse metadata and raw pulse data with padding .
The padding block will append zeros to the data to ensure that the total amount of data measured
over one padding frame is at least equal to the minimum frame length . Setting the minimum frame length
to zero disables the padding.

Note
The padding functionality is disabled by setting the minimum record length to zero.
The padding is applied to each padding frame after a certain offset. The padding offset is equal to
the detection window length in pulse metadata mode. The padding is configured using the API call
PDSetupCharacterization()
. How the padding frame is set up depends on the data collection mode,
see Table 5 .
For pulse metadata mode the padding data is appended to the data record, whereas for the raw pulse
data with padding mode a new record is generated with the padding data.
4.11 User Space Record
User space records are the records of data received by the user. A record consists of a data part and a
header part. The header includes information about e.g. the length and the trigger timestamp.
The contents of the user space records will depend on the data collection mode. In all modes but
the metadata mode, the record will consist of the data sampled by the ADC. In the metadata mode, the
record will consist of the pulse metadata packets.
The raw data records can either have a fixed length or a variable length . Fig. 6 illustrates the dif-
ferences between the two record types. The length of a metadata record will depend of the number of
pulses detected.
4.11.1 Fixed Length Record
A fixed length record is defined by the trigger event and the record length. The length of a fixed length
record is specified by the user, and is independent of the data collected. A fixed length record can be
triggered by any of the trigger sources.
4.11.2 Variable Length Record
The length of a variable length record will depend on the data. A variable length record is defined as the
data between the trigger event and reset event. If trailing or leading edge windows are used, these will
also be included in the record.
If two pulses have overlapping trailing and leading edge windows, they will be concatenated into one
single record. This is illustrated in Fig. 6 . The variable length mode can only be used with the level
trigger.
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