Recommendations for the Use of Programmable Logic Controllers (PLCs) at CERN

Programmable Logic Controllers (PLCs) have been increasingly used at CERN for several years. In future control solutions, PLCs will initially be considered for the rejuvenation of old and obsolete systems, and then for the control of new equipment to be installed in technical services, accelerators and experiments. Many industrial systems will be installed for the control of equipment during the next 5 to 10 years, particularly for the construction of the LHC project. In order to increase efficiency, to reduce the initial investment and to minimise the long term maintenance costs in terms of money and human resources the Working Group recommends that all CERN equipment control projects, based on PLCs, select or specify PLCs from the product lines of the recommended PLC manufacturers.