Pre-Processing

In general the following programs do not require cooked data to provide useful output and can be run on the raw data file before processing.

• sync: About every thousand events or so during data taking, the readout controllers send a synchronization signal to the event builder to check whether event fragments have been lost. If one of these sync events is bad all of the data for the past thousand events could be corrupted. Therefore, it is counter productive to cook those thousand events. The sync program skims through the raw data file and writes out a text file that contains a list of event numbers between which there was a bad synchronization event. This text file can be used by a1 to skip unsynchronized events. Obviously, this program must be run before a1c is run.
• scaler_mon: scaler_mon integrates quantities found in the scaler banks needed for normalization. These quantities include the Faraday Cup information (for electron running) and the T counter scalers (for photon running). The text file (to stdout) produced by this program contains the integrated scalers for each data file. In addition, a Perl script called gscalers2map located in CLAS_SCRIPTS was developed for photon running to update the map for tagger normalization from the scaler_mon output text file.