The 5 MW proton linear accelerator of the European Spallation Source ERIC is designed to accelerate the beam at a repetition rate of 14 Hz, which dictates the refresh rate of most of the relevant data produced by acquisition systems. Each cycle of the 14 Hz timing structure receives a unique cycle ID from the ESS Timing System, which can be used as an index when data is collected and stored. The ESS Linac Synchronous Data Service (SDS) facilitates the collection of high-resolution data from various accelerator subsystems. Currently, SDS consists of an EPICS extension to be included in data acquisition IOCs and a client service (SDS Collector) that collects and stores the data produced by these IOCs. The novel features provided by the EPICS PVAccess protocol and libraries play a crucial role in this project by supporting structured data in the EPICS Process Variable data format. This paper outlines how SDS is designed, how it enables data-on-demand and post-mortem collection of large array datasets without overloading the network and describes the results of using SDS during the latest ESS beam commissioning campaign in 2025. From a broader perspective, SDS will be part of the ESS Data Framework, which comprises a set of tools to collect, store, catalog, retrieve, and analyze ESS Linac data to support advanced applications such as machine learning algorithms. This framework is briefly described in this paper.

As commissioning activities for the Linear accelerator continues at the European Spallation Source (ESS), it is highlighting important issues and development features for the MTCA.4 systems used in several key subsystems. With over 300 MTCA.4 systems deployed for Low Level Radio Frequency (LLRF), Proton Beam Instrumentation (PBI), Fast Beam Interlock Systems (FBIS), and Timing Distribution (TD), it has proved a valuable platform for fast controls. The use of MTCA.4 has also allowed for novel solutions to provide flexible but reliable controls for the facility, including expanding existing controls design and developing orphan scope. However this is not without its issues, as MTCA.4 for the scientific community is still very much on the smaller scale and reliant on only a few suppliers, with risk of obsolesce of components and changes to the standards. This makes it challenging but fun to continue developing the hardware to ensure the desired reliability for the Linac controls. This paper will describe the procedures and processes that the hardware team has taken to mitigate these issues, the current status of our MTCA infrastructure and the long term plans for its maintenance.

The European Spallation Source facility is divided in three main parts: linear accelerator (LINAC), target and neutron instruments. The Beam Position Monitor (BPM) system is installed along the LINAC and enables accelerator teams to characterize the proton beam properties and optimize the phase tuning of the RF cavities, among other diagnostics. A total of 98 BPM sensors are distributed along the machine, with data acquisition and processing handled by 49 AMC digitizer cards housed in 18 MicroTCA crates. This paper describes the control system architecture surrounding the BPM system, including the EPICS integration alongside the graphical user interface developed in Control System Studio. Additionally, it presents the high-level applications built on top of this framework, such as the BPM Manager, Gain Controls, Archiver, and Synchronous Data Service. The paper also outlines the software strategy adopted for system deployment, maintenance, and updates. Auxiliary systems supporting the BPM infrastructure are briefly discussed, including the BPM components controls, MicroTCA IPMI management and the MRF Timing System integration.

The 5 MW proton linear accelerator of the European Spallation Source ERIC is designed to accelerate the beam at a repetition rate of 14 Hz, which dictates the refresh rate of most of the relevant data produced by acquisition systems. Each cycle of the 14 Hz timing structure receives a unique cycle ID from the ESS Timing System, which can be used as an index when data is collected and stored. The ESS Linac Synchronous Data Service (SDS) facilitates the collection of high-resolution data from various accelerator subsystems. Currently, SDS consists of an EPICS extension to be included in data acquisition IOCs and a client service (SDS Collector) that collects and stores the data produced by these IOCs. The novel features provided by the EPICS PVAccess protocol and libraries play a crucial role in this project by supporting structured data in the EPICS Process Variable data format. This paper outlines how SDS is designed, how it enables data-on-demand and post-mortem collection of large array datasets without overloading the network and describes the results of using SDS during the latest ESS beam commissioning campaign in 2025. From a broader perspective, SDS will be part of the ESS Data Framework, which comprises a set of tools to collect, store, catalog, retrieve, and analyze ESS Linac data to support advanced applications such as machine learning algorithms. This framework is briefly described in this paper.