On-Change Publishing of Database Resident Control System Data

The CERN accelerator control system is largely data driven, based on a distributed Oracle® database architecture. Many application programs depend on the latest values of key pieces of information such as beam mode and accelerator mode. Rather than taking the non-scalable approach of polling the database for the latest values, the CERN control system addresses this requirement by making use of the Oracle Advanced Queuing – an implementation based on JMS (Java Message Service) – to publish data changes throughout the control system via the CERN Controls Middleware (CMW). This paper describes the architecture of the system, the implementation choices and the experience so far

Controls Middleware: the New Generation

A new Controls Middleware (CMW) for the "LHC era" has been recently designed and implemented to serve the CERN accelerator sector. It is object-oriented and supports two conceptual models: The Device model traditionally used in accelerator controls and the Topic model, which is widely used in the commercial world. Unlikely previous middleware solutions, developed in the 80's, this middleware is completely build upon commercial standards: CORBA for synchronous calls, JMS (Java Message Service) for message passing and OPC (OLE for Process Control) for integration of industrial equipment. The subscription paradigm is supported in both Device and Topic models. This paper presents the system architecture and an overview of the user facilities and API's. The experience with CMW, the issues of integration of CORBA, JMS and OPC and system administration are addressed as well

Assembling and testing of quasi-static hybrid piezoelectric motor based on electroactive lubrication principle

The presented paper concerns a novel concept of hybrid piezoelectric motor based on electroactive lubrication principle. Its structure is combined of quasi-static and resonance piezoelectric actuators, synchronizing their work to generate the rotary movement. The hybrid motor topology is compared to the existing piezoelectric motors, regarding its field of applications in embedded systems with very high security requirements. The electroactive lubrication principle is briefly presented with regards to optimization of the hybrid motor. The performance principle of the hybrid motor is described in terms of its working cycle. The assembling process of the prototype hybrid motor is briefly explained with emphasis put on the frequency and impedance tuning of the applied quasi-static and resonance piezoelectric actuators. Next, the hybrid motor power supply system is described and chosen measured performance characteristics are presented. Finally, conclusions concerning the features of the tested prototype hybrid motor and possible solutions of the faced issues, during assembling and testing, are presented