Teledyne SP Devices ADQ14, User Manual

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Classification Revision
Public PA1
Document ID Print date
18-2074 2018-04-06
number by
Bin[n] =
( x + δ )
·
α
1024
, (5)
where x is the histogram metadata value,
δ
is an offset and
α
is a scale factor.
In addition to the normal histogram data bins, each histogram has an overflow and underflow bin.
These bins are used if the resulting bin number from ( 5 ) is outside of the allowed range. That is if the bin
number is smaller than zero the underflow bin will be incremented by one. Conversely, if the bin number
is larger the total number of bins the overflow bin will be incremented by one.
The histogram underflow and overflow bins are accessed by calling
PDGetHistogramStatus()
.

Example
Let a certain pulse have the peak value -5000 and the peak value histogram be configured with scale
factor α = 1024 and the offset δ = 4000 . The resulting bin number would be -1000 , from ( 5 ). Since
this is less than 0, the underflow bin would be incremented by one.
The API calls used to interface with the histograms are listed below. Please refer to the ADQAPI reference
guide [ 3 ] for details on the usage.
•
PDReadHistogram()
•
PDReadHistogramStatus()
•
PDClearHistogram()
•
PDSetupHistogram()
4.9.1 Overflow
The average processing bandwidth of the histogram is roughly 33 million pulses / second. For short
bursts of pulses a buffering FIFO is implemented. If the number of pulses exceeds the processing band-
width, a overflow flag will be set. The flag can be accessed by calling
ReadHistogramStatus()
.
The overflow status is reset by clearing the histograms.

Note
The histogram can process 33 million pulses / second on average. The
ReadHistogramStatus()
API
call can be used to detect an overflow.
Table 4: The number of bins for the different histogram types.
Type Number of bins
Pulse peak value 16384
Pulse width 4096
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