A general software module for CAMAC, equipment and composite variable control

Abstract

Current PS controls application software has a strong hierarchical structure of software modules which translate user-friendly commands into the intricacies of hardware devices. Starting from the most elementary hardware level, these are: (i) the "interface module" (IM), which hides the various CAMAC commands so as to provide a standard access to each type of CAMAC module ; (ii) the "equipment module" (EM) presents a simple standard software interface of each process equipment. There is one EM for each type of equipment and all process equipment is accessed through EMs via IMs; (iii) the "composite variable module" (CVM) provides control of abstract beam variables. It involves control of several and possibly different kinds of equipment. Setting a CVM results in appropriate setting of all relevant equipment through calls to their EMs.For the LEP Preinlector (LPI) a new generation of application software is being implemented based on the experiments with the current system and the technological evolution since its conception. The logical levels of IM, EM and CVM are kept, but their managerial and housekeeping functions are merged into a single module : the "General Module" (GM) .This paper represents the characteristics of the GM, its decomposition into housekeeping and management activities ones to supervise device specific controls, and its structuring into logic and data modules. This results m a unique frame for all modules in the application hierarchy. It is transparent to the programmes so that the development of specific IMs, EMs and CVMs reduces to editing appropriate data tables, developing specific codes or re-using existing ones . Thus new generation of application software follows modern ideas on conceptual modelling by data abstraction and object-oriented programming.

Computer control for the CERN ISOLDE-3 project

“…With three CAMAC assemblies and five software packages nearly all the main control tasks have been realised. The software packages are called Equipment Modules (EM) [12 ].…”

A general software module for CAMAC, equipment and composite variable control

“…Myers' ideas and terminology have been applied to evaluate the decomposition of the CPS control application software system . The detailed investigation can be found in [5], here we give only the results .…”

Process equipment data organisation in CERN PS controls

“…The controls for the PS accelerator complex have from the beginning accessed the accelerator equipment through a unique call interface ("Equipment Module") and data format (by classes of equipment, one data record per piece of equipment of the same class) (1). The action to be executed is indicated by a 'property" which causes a set of statements, the "property-code', to be executed.…”