In DELPHI the full online system is controlled through this mechanism, the various areas of DELPHI have been mapped into SMI domains: sub-detector domains, DAS domain, SC domain, TRIGGER domain, etc. The full system comprises about 1000 SMI objects in 50 different domains.
A high level of automation of the experiment's control system is very important in order to avoid human mistakes and to speed up standard procedures.
Using the SMI mechanism the creation of a top level domain - BIG BROTHER - containing the logic allowing the interconection of the underlying domains (LEP, DAS, SC, etc.) was a very easy task. Figures 4-1 Big-Brother Control
Under normal running conditions BIG BROTHER pilots the system with minimal operator intervention as shown in Figure Figure 4-1. In other test and setup periods the operator becomes the top-level object, using the user-interfaces he can send commands to any SMI domain.