Observing - System Libraries (J.Quick)

To the astronomers the observing is one of the most visible and important parts of the system. The NCCS proposes to change fundamentally the way observing is done at HartRAO. On the old HP1000 control system observing programs were written in Fortran. Setting up the system was done directly by the observing program at a very low level. Although some common subroutines and/or examples for certain procedures existed observing programs often needed to know about the system at a very low-level and much code duplication exists. Modification of multiple programs to reflect any new system change takes a long time and is highly inefficient.

The NCCS proposes to implement all system aspects up to a very high level as atomic ``system commands''. These actions will be directly callable either from an interactive shell, or directly from observing programs written in an interpreted high level observing language, or in C. Accessing of system parameters will only be possible via these system commands. This will ensure there is only one implementation of each system command functionality. Observing programs should no longer need to worry about low-level system aspects anymore (e.g. device details like addresses, data formats etc.). Writing programs in an interpreted language also ensures that modifications can be done rapidly on-the-fly. All these system commands will be implemented only once in C as an ELF dynamically loadable library (DLL). This will ensure only that the most current version of each command is in use.

Tasks still to be done :

$\Longrightarrow$

DEFINE A SUITABLE SET OF BASIC SYSTEM COMMANDS TO BE IMPLEMENTED,

$\Longrightarrow$

CONSTRUCT A DYNAMICALLY CONFIGURABLE SYSTEM SETUP RESOURCE DATABASE,

$\Longrightarrow$

IMPLEMENT ALL COMMANDS IN C AND GENERATE OBSERVING SHARED LIBRARY.