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Sometimes data for a particular shot can not be read out because DAQ data buffers are unavailable. This is called "deadtime". Deadtime can make it impossible to reliably use high-rate shots to perform operations like normalizations for lower-rate integrating detectors. Matt Weaver is adding counters to the timing system so the DAQ can count how many shots whose data has been dropped due to deadtime so experimenters can make a decision about whether there is sufficient data for a normalization-style analysis.
This example example demonstrates (conceptually!) how to do the normalization, and view the results in a psmon plot (use the command "psplot ANDOR" on the same node). Run this script either with "python andor.py" or "mpirun -n 5 andor.py":
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from psana import DataSource
from psmon import publish
from psmon.plots import Image,XYPlot
import os
from mpi4py import MPI
comm = MPI.COMM_WORLD
rank = comm.Get_rank()
size = comm.Get_size()
os.environ['PS_SRV_NODES']='1'
if rank==4: # hack for now to eliminate use of publish.local below
publish.init()
# we will remove this for batch processing and use "psplot" instead
# publish.local = True
def my_smalldata(data_dict):
if 'unaligned_andor_norm' in data_dict:
andor_norm = data_dict['unaligned_andor_norm'][0]
myplot = XYPlot(0,"Andor (normalized)",range(len(andor_norm)),andor_norm
)
publish.send('ANDOR',myplot)
ds = DataSource(exp='rixx1003821',run=46,dir='/cds/data/psdm/prj/public01/xtc',intg_det='andor_vls',batch_size=1)
for myrun in ds.runs():
andor = myrun.Detector('andor_vls')
timing = myrun.Detector('timing')
smd = ds.smalldata(filename='mysmallh5.h5',batch_size=1000, callbacks=[my_smalldata])
norm = 0
ndrop_inhibit = 0
for nstep,step in enumerate(myrun.steps()):
print('step:',nstep)
for nevt,evt in enumerate(step.events()):
andor_img = andor.raw.value(evt)
# also need to check for events missing due to damage
# (or compare against expected number of events)
ndrop_inhibit += timing.raw.inhibitCounts(evt)
smd.event(evt, mydata=nevt) # high rate data saved to h5
# need to check Matt's new timing-system data on every
# event to make sure we haven't missed normalization
# data due to deadtime
norm+=nevt # fake normalization
if andor_img is not None:
print('andor data on evt:',nevt,'ndrop_inhibit:',ndrop_inhibit)
# check that the high-read readout group (2) didn't
# miss any events due to deadtime
if ndrop_inhibit[2]!=0: print('*** data lost due to deadtime')
# need to prefix the name with "unaligned_" so
# the low-rate andor dataset doesn't get padded
# to align with the high rate datasets
smd.event(evt, mydata=nevt,
unaligned_andor_norm=(andor_img/norm))
norm=0
ndrop_inhibit=0 |
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