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The ASSOCIATION Field

This field is used to specify that another parameter is to be associated with this parameter. The value of the associated parameter is one of the options available to be used as the value of this parameter. Furthermore, the value of a parameter can be used to automatically update the value of its associated parameter on successful completion of the program.

This behaviour is primarily of relevance to ADAM A-tasks. I-tasks can obtain parameter values from an association, but do not write parameters on completion.

The field is of the form:

ASSOCIATION  association-specification
where association-specification is a character string consisting of two parts - an association operator followed by a parameter specifier.

There are three association operators:

Currently, only global parameters may be associated with program parameters - they are stored in the GLOBAL data structure and provide a common pool of parameter values for programs in an integrated system. Global parameters can be created by the association write mechanism or by an ICL CREATEGLOBAL or SETGLOBAL command. They may also be read into ICL variables by the GETGLOBAL command. It is necessary to be careful when multi-tasking in ADAM because an error will occur if two programs attempt to update the GLOBAL data structure simultaneously.

The specifier of a global parameter is of the form:

GLOBAL.parameter_name
If the ASSOCIATION field is omitted, no association is made.





next up previous 63
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ADAM Interface Module Reference Manual
Starlink User Note 115
A J Chipperfield, B D Kelly, S L Wright
3 September 2002
E-mail:ussc@star.rl.ac.uk

Copyright © 2002 Council for the Central Laboratory of the Research Councils