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FakeISISEventDAE v1¶

../_images/ImageNotFound.png — Enable screenshots using DOCS_SCREENSHOTS in CMake¶

Summary ¶

Simulates ISIS event DAE.

Properties ¶

Name	Direction	Type	Default	Description
NPeriods	Input	number	1	Number of periods.
NSpectra	Input	number	100	Number of spectra.
Rate	Input	number	20	Rate of sending the data: stream of NEvents events is sent every Rate milliseconds.
NEvents	Input	number	1000	Number of events in each packet.
Port	Input	number	59876	The port to broadcast on (default 59876, ISISDAE 10000).

Description ¶

Simulates ISIS event DAE. It runs continuously until canceled and listens to port 10000 for connection. When connected starts sending event packets.

Events are randomly distributed between the following

Periods
Spectra
time of flight between 10,000 and 20,000

Usage ¶

Example:

from threading import Thread
import time

def startFakeDAE():
    # This will generate 2000 events roughly every 20ms, so about 50,000 events/sec
    # They will be randomly shared across the 100 spectra
    # and have a time of flight between 10,000 and 20,000
    try:
        FakeISISEventDAE(NPeriods=1,NSpectra=100,Rate=20,NEvents=1000)
    except RuntimeError:
        pass

def captureLive():
    ConfigService.setFacility("TEST_LIVE")

    try:
        # start a Live data listener updating every second, that rebins the data
        # and replaces the results each time with those of the last second.
        StartLiveData(Instrument='ISIS_Event', OutputWorkspace='wsOut', UpdateEvery=1,
                      ProcessingAlgorithm='Rebin', ProcessingProperties='Params=10000,1000,20000;PreserveEvents=1',
                      AccumulationMethod='Add', PreserveEvents=True)

        # give it a couple of seconds before stopping it
        time.sleep(2)
    finally:
        # This will cancel both algorithms
        # you can do the same in the GUI
        # by clicking on the details button on the bottom right
        AlgorithmManager.cancelAll()
        time.sleep(1)
#--------------------------------------------------------------------------------------------------

oldFacility = ConfigService.getFacility().name()
thread = Thread(target = startFakeDAE)
thread.start()
time.sleep(2) # give it a small amount of time to get ready
if not thread.is_alive():
    raise RuntimeError("Unable to start FakeDAE")

try:
    captureLive()
except:
    print("Error occurred starting live data")
finally:
    thread.join() # this must get hit

# put back the facility
ConfigService.setFacility(oldFacility)

#get the output workspace
wsOut = mtd["wsOut"]
print("The workspace contains %i events" % wsOut.getNumberEvents())