C. Lazaridis

SWATCH: common control SW for the uTCA-based upgraded CMS L1 Trigger

The CMS L1 Trigger electronics are composed of a large number of different cards based on the VMEBus standard. The majority of the system is being replaced to adapt the trigger to the higher collision rates the LHC will deliver after the LS1, the first phase on the CMS upgrade program. As a consequence, the software that controls, monitors and tests the hardware will need to be re-written. The upgraded trigger will consist of a set of general purpose boards of similar technology that follow the TCA specification, thus resulting in a more homogeneous system. A great effort has been made to identify the common firmware blocks and components shared across different cards, regardless of the role they play within the trigger data path. A similar line of work has been followed in order to identify all possible common functionalities in the control software, as well as in the database where the hardware initialisation and configuration data are stored. This will not only increase the homogeneity on the software and database sides, but it will also reduce the manpower needed to accommodate the online SW to the changes on hardware. Due to the fact that the upgrade will take place in different stages, it has been taken into consideration that these new components had to be integrated in the current SW framework. This paper presents the design of the control SW and configuration database for the upgraded L1 Trigger.

SWATCH: Common software for controlling and monitoring the upgraded level-1 trigger of the CMS experiment

The Large Hadron Collider at CERN restarted in 2015 with a higher centre-of-mass energy of 13TeV. The instantaneous luminosity is expected to increase significantly in the coming years. An upgraded Level-1 trigger system has been deployed in the Compact Muon Solenoid experiment, in order to maintain the same efficiencies for searches and precision measurements as those achieved in the previous run. This system consists of the order of 100 electronics boards connected by the order of 3000 optical links, which must be controlled and monitoring coherently through software, with high operational efficiency. In this paper, we present the design of the software framework that is used to control and monitor the upgraded Level-1 trigger system, and experiences from using this software to commission the upgraded system.

SWATCH Common software for controlling and monitoring the upgraded CMS Level-1 trigger

The CMS Level-1 Trigger has been replaced during the first phase of CMS upgrades in order to cope with the increase of centre-of-mass energy and instantaneous luminosity at which the LHC presently operates. Profiting from the experience gathered in operating the legacy system, effort has been made to identify the common aspects of the hardware structures and firmware blocks across the several components (subsystems).

The architecture of the CMS Level-1 Trigger Control and Monitoring System using UML

The architecture of the Compact Muon Solenoid (CMS) Level-1 Trigger Control and Monitoring software system is presented. This system has been installed and commissioned on the trigger online computers and is currently used for data taking. It has been designed to handle the trigger configuration and monitoring during data taking as well as all communications with the main run control of CMS. Furthermore its design has foreseen the provision of the software infrastructure for detailed testing of the trigger system during beam down time. This is a medium-size distributed system that runs over 40 PCs and 200 processes that control about 4000 electronic boards. The architecture of this system is described using the industry-standard Universal Modeling Language (UML). This way the relationships between the different subcomponents of the system become clear and all software upgrades and modifications are simplified. The described architecture has allowed for frequent upgrades that were necessary during the commissioning phase of CMS when the trigger system evolved constantly. As a secondary objective, the paper provides a UML usage example and tries to encourage the standardization of the software documentation of large projects across the LHC and High Energy Physics community.