Data sources are generally used to feed fixed messages to a model at fixed stages of processing. Their usual function is to act as input devices, where they can feed a stream of input to the model. This input stream consists of a list of messages. Any Prolog term can be passed as a message, so data sources can be used to feed information of arbitrary complexity into a model. Data sources can also send multiple messages on a single cycle (including messages to different boxes). Thus, they can be used to trigger rules in a process (see below), or to add elements to a buffer.
Data sources do not have any properties associated with them. Unlike other classes of box, where properties can be used to configure behaviour for specific purposes, the general behaviour of data sources is fixed. This is because the flexibility in the specification of messages to be sent by sources has, to date, proved sufficient.
As with all COGENT objects, there is no limit to the number of data sources you can have in one model, and they will all behave as independent devices.
A source contains a set of source elements, each source element consisting of a set of actions.
Open the source and select its Initial Contents tab. Double click on the source element to be edited. The source element will then be opened for editing with the rule editor.
Open the source and select its Initial Contents tab then Select the Insert->Source Element menu item. The rule editor is then displayed allowing the new element to be defined.