  The four LHC experiments at CERN have decided to use a commercial SCADA
(Supervisory Control And Data Acquisition) product for the supervision of their
DCS (Detector Control System). The selected SCADA, which is therefore used for
the CMS DCS, is PVSS II from the company ETM. This SCADA has its own database,
which is suitable for storing conventional controls data such as voltages,
temperatures and pressures. In addition, calibration data and FE (Front-End)
electronics configuration need to be stored. The amount of these data is too
large to be stored in the SCADA database [1]. Therefore an external database
will be used for managing such data. However, this database should be
completely integrated into the SCADA framework, it should be accessible from
the SCADA and the SCADA features, e.g. alarming, logging should be benefited
from. For prototyping, Oracle 8i was selected as the external database manager.
The development of the control system for calibration constants and FE
electronics configuration has been done in close collaboration with the CMS
tracker group and JCOP (Joint COntrols Project)(1).
  (1)The four LHC experiments and the CERN IT/CO group has merged their efforts
to build the experiments controls systems and set up the JCOP at the end of
December, 1997 for this purpose.
