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Description of TES
PseudoCode
This is a proposed algorithm to handle the data produced by the TES detectors for LCLS-II.
The data is assumed to consist of several time streams per FPGA (250) sampled at 1 MHz. The beam repetition rate is 10 kHz, for a total of 100 samples minimum between valid (photon generated) events. The samples are assumed to be 16 bits.
Parfor : Parallel For
NumberOfChannels : number of channels to be handles by the FPGA
Samples per Window : Number of samples in a single pulse window
TotalNumberOfWindows : Maximum number of windows to be kept in memory for the configured filters. Currently only 3 for a total of four cases. The active window, the preceding one and the following one. Possibly more windows to be added before/after for more precision in the energy measurement.
Active Window : Window on which we are performing the filter calculation
Current Window : Window that is currently loading in buffers.
EventMatrix : Matrix containgin information about the presence of events in each window of each channel.
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CreateCircularBuffers (NumberOfChannels,
SamplesPerWindow, TotalNumberOfWindows)
LoadFilters()
ConfigureDataChannel()
While IncomingData:
LoadDatainBuffers()
ApplyCrosstalkCorrection(All_Channels,CurrentWindow)
EventMatrix = TagEvents(All_Channels)
For each ActiveWindow :
WindowIncrement=+1
Parfor each Channel:
Switch (CheckEvents(EventMatrix)):
Case No Event Before And After
Energy = ApplyFilter(Filter00)
Case Event Before And After
Energy = ApplyFilter(Filter11)
Case Event Before Only
Energy = ApplyFilter(Filter10)
Case Event After Only
Energy = ApplyFilter(Filter00)
SaveEnergyAndTimestamp(xtcFile)
If WindowIncrement == SaveIncrement
SaveWaveformtoXTC(xtcFile, TotalTimeWindow, AllChannels)
Def TagEvents:
Parfor each channel :
If Slope > MinimumSlope:
CurrentWindowEvent=True
Else:
CurrentWindowEvent=False
EventMatrix(channel, currentWindowIndex) = CurrentWindowEvent
Return EventMatrix
Def ApplyFilter(Filter):
For each i, sample :
Temp = linearFunction(sample) * sample
Temp = temp* Filter(i) *Filter2(i) %More filters added if necessary
Energy = sum(temp)
%Details on operations required for this step
% Can we pipeline the linear function with the multiply and add? |
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