SCADA (Supervisory Control and Data Acquisition) systems traditionally acquire data from PLCs through polling. The Time Stamped Push Protocol (TSPP), on the other hand, enables a PLC to timestamp and push data to the SCADA at its own discretion. The Vacuum Control Systems for CERN accelerators are primarily built on a dedicated Vacuum Framework, which relies on polling and is therefore subject to its limitations. Implementing TSPP would thus be an important improvement. TSPP needs software on the PLC – a Data Manager - to determine what data to push, when to push it, and how to package it into the correct format. Due to its particular data model, implementing TSPP for the Vacuum Framework required the development of a dedicated Data Manager. Additionally, while most current systems with TSPP have a single PLC per SCADA instance, Vacuum Framework applications often involve hundreds. Given that no data was available on the impact that large numbers of PLCs pushing data to a SCADA system might have, extensive testing was required. In particular, the relationship between server load and the effective rate of received values was studied to assess performance at scale. This paper details the implementation of TSPP for the Vacuum Framework, its Data Manager design, and the testing carried out to validate the protocol and assess its performance limits in order to ensure a smooth deployment.

SCADA (Supervisory Control and Data Acquisition) systems traditionally acquire data from PLCs through polling. The Time Stamped Push Protocol (TSPP), on the other hand, enables a PLC to timestamp and push data to the SCADA at its own discretion. The Vacuum Control Systems for CERN accelerators are primarily built on a dedicated Vacuum Framework, which relies on polling and is therefore subject to its limitations. Implementing TSPP would thus be an important improvement. TSPP needs software on the PLC – a Data Manager - to determine what data to push, when to push it, and how to package it into the correct format. Due to its particular data model, implementing TSPP for the Vacuum Framework required the development of a dedicated Data Manager. Additionally, while most current systems with TSPP have a single PLC per SCADA instance, Vacuum Framework applications often involve hundreds. Given that no data was available on the impact that large numbers of PLCs pushing data to a SCADA system might have, extensive testing was required. In particular, the relationship between server load and the effective rate of received values was studied to assess performance at scale. This paper details the implementation of TSPP for the Vacuum Framework, its Data Manager design, and the testing carried out to validate the protocol and assess its performance limits in order to ensure a smooth deployment.

The HL-LHC project has initiated a comprehensive upgrade of the LHC vacuum control system. Much of the vacuum control hardware, installed at the beginning of the LHC in 2008 or even dating back to the LEP era in the 1990s, was becoming obsolete and required modernization. Additionally, the new HL-LHC operating conditions will induce higher radiation levels; therefore, new radiation-tolerant electronics are required in the arcs and dispersion suppressor areas, as well as radiation-hard equipment in the matching sections. Moreover, during the third long shutdown (2026-2030), the matching sections around the ATLAS and CMS experiments will need to be extensively modified with the insertion of new systems. The vacuum control system will be relocated to new underground galleries, with a significant increase in vacuum control equipment. This upgrade, progressively implemented during each year-end technical stop and long shutdown, spans from 2019 to 2030. Hundreds of controllers are involved, along with significant control software design and refactoring, while keeping the vacuum control system fully operational. This paper provides an overview of the new designs and technological solutions chosen, the radiation hardness assurance applied, the evolution of the vacuum control system architecture, and the main control software upgrades to ensure decades of reliable operation. Furthermore, it presents the current progress, challenges, and outlines future activities planned until 2030.