Data analysis can be partitioned into two modes of operation.
Inline analysis is defined as all data processing that is performed by the data acquisition system during the acquisition of the raw data. This code resides in the Event Builder VME crate.
Online analysis is defined as all data processing which takes place in real-time on the formatted data. This code resides in a UNIX workstation or PC.

• Inline Data Processing. This has to process all the raw data events before sending them to tape. In addition to the basic functions of event building, data checking and event formatting it can also include as user selectable options functions such as doppler correction and calibration (gain matching).
  In this case it is necessary to consider the impact of such processing on the final data rate. Also any errors introduced may seriously effect the correct output of data to tape.

• Online Data Processing. The Event Builder generates formatted data blocks which are transmitted via the data network (100Tx ethernet) to the tape server where they are written onto tape. Any workstation or PC with a connection to the data network has access to the formatted data and users can run any data analysis code they wish in a manner very similar to online data analysis from tape.
  A procedure library will be provided which will return formatted data blocks in exactly the same format as written to tape.
  In this mode of operation the correct or otherwise operation of the software can have no effect on the output of data to tape and is thus a more secure mode of operation.