CREAM data

Zero suppression

After L1 the data from the CREAMs is requested with so called MRPs. These store a flag called requestZeroSuppressed which can be set in two different ways:

Global setting

The farm can be started with a flag called --sendMRPsWithZSuppressionFlag. Set to 0 no zero suppressed data will be requested. If set to true it depends on the following setting:

L1 word specific setting

If --sendMRPsWithZSuppressionFlag is set to 1 you can still request non zero suppressed data by returning false in the method L1TriggerProcessor::isRequestZeroSuppressedCreamData.

Currently the default behaviour is that all bypassed events are automatically requesting zero suppressed data. This can be used to read out a small fraction (e.g. 1%) of the events without zero suppression by using the following parameters:

--sendMRPsWithZSuppressionFlag=0 --L1BypassProbability=0.01

If you want to request non zero suppressed data for the specific L1 trigger type word MY_WORD you could change the code to something similar to following

return l1TriggerTypeWord != TRIGGER_L1_BYPASS && l1TriggerTypeWord != MY_WORD;