TPC State Diagram

Click on the image for a postscript file.....

In the simulation the TPC, SVT and XTPC are treated in the same manner so that the discussion here also reflects functions of the SVT and XTPC.

A trigger result is initially broadcast to the detector. If the broadcast is decoded such that it involves a TPC trigger the object begins the drift period. This is a WAIT of 100 microseconds. If the drift is aborted the 100 microsecond WAIT is completed and 2 microseconds is added reflecting the reset time of the TPC. The TPC object is then reset and can accept another event.

Upon completion of the drift, the object begins the digitization method. The WAIT period associated with digitization is 10 milliseconds. If digitization is aborted the procedure is interrupted and a 2 microsecond reset WAIT is implemented. While the detector is drifting or digitizing the BUSY=TRUE flag is set so that no other TPC events can be triggered.

Upon completion of digitization there is a 200 microsecond WAIT which corresponds to a DAQ busy for processing of the event. This will be updated with the addition of Level 3 and Level 4 objects to the model (see Future Additions ).

Back to the Object Model .
J.P. Whitfield, Carnegie Mellon 4/20/95