ILMU AUTOMATION

1. Introduction

On 20 Sept. 2000, the Finance Committee approved the proposal to negotiate a contract with ETM A.G. (Eisenstadt, Austria) for the supply of PVSS - ETM's SCADA - for developing the control systems of ALICE, ATLAS, CMS and LHCb. In addition the SCADA Working Group, that was set up by the CERN Controls Board, recommends PVSS as one of the SCADA products for the development of future control systems at CERN.

These decisions are the accomplishment of around thirteen person-years (FTE) of effort - spanning over more than three years - to identify and evaluate a proper industrial control system that copes with the extreme requirements of high energy particle physics experiments such as those of the LHC.

Widely used in industry for Supervisory Control and Data Acquisition of industrial processes, SCADA systems are now also penetrating the experimental physics laboratories for the controls of ancillary systems such as cooling, ventilation, power distribution, etc. More recently they were also applied for the controls of smaller size particle detectors such as the L3 muon detector and the NA48 experiment, to name just two examples at CERN.

SCADA systems have made substantial progress over the recent years in terms of functionality, scalability, performance and openness such that they are an alternative to in house development even for very demanding and complex control systems as those of physics experiments.

2. What does SCADA MEAN?

SCADA stands for Supervisory Control And Data Acquisition. As the name indicates, it is not a full control system, but rather focuses on the supervisory level. As such, it is a purely software package that is positioned on top of hardware to which it is interfaced, in general via Programmable Logic Controllers (PLCs), or other commercial hardware modules.

SCADA systems are used not only in industrial processes: e.g. steel making, power generation (conventional and nuclear) and distribution, chemistry, but also in some experimental facilities such as nuclear fusion. The size of such plants range from a few 1000 to several 10 thousands input/output (I/O) channels. However, SCADA systems evolve rapidly and are now penetrating the market of plants with a number of I/O channels of several 100 K: we know of two cases of near to 1 M I/O channels currently under development.

SCADA systems used to run on DOS, VMS and UNIX; in recent years all SCADA vendors have moved to NT and some also to Linux.