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Paper: Generic Abstraction of Hardware Control Based on the ALMA Common Software
Volume: 314, Astronomical Data Analysis Software and Systems XIII
Page: 748
Authors: Jeram, B.; Chiozzi, G.; Ibsen, J.; Cirami, R.; Pokorny, M.; Muders, D.; Wischolek, D.
Abstract: The ALMA Common Software (ACS) is a CORBA-based framework that provides a common and homogeneous infrastructure for the whole ALMA software, from high-level data flow applications down to instrument control (Schwarz et al., 2004). This paper focuses on ACS support for the development of Control System applications. In this domain, ACS provides a generic abstraction of hardware control and monitor points that is independent of the software underneath. This abstraction layer is coupled to the hardware using the DevIO (Device Input/Output) interface, based on the Bridge design pattern. Application developers have to implement DevIO classes that handle the details of the communication with the hardware.

ACS itself provides a default DevIO implementation which simply writes and reads into/from a memory location. Currently there are two other major DevIO implementations available: a CAN bus communication, used by ALMA, and a socket based implementation used by the Atacama Pathfinder EXperiment (APEX) project.

In spite of using different hardware and control electronics, the DevIO abstraction allows the ALMA and APEX projects to have the same device architecture down to the level of the DevIO implementation.

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