CoolBOT Port Automata

Components are modeled as Port Automata in CoolBOT. This concept establishes a clear distinction between the internal functionality a pf an active entity, its set of input and output port, the automation and its external functionality. The active components entities which carry out specific tasks and perform all external communication by means of their input and output ports. Components cat their own initiative, running in concurrently or parallel, and are normally weakly coupled, e.g. no acknowledgements are necessary when they communicate through their ports.

CoolBOT components inter communicate and interact each other by means of port connections established among their input and output ports. Data are transmitted through connections port in discrete units called port packets. Port packets are defined as units of discrete of information which can be received through input ports, and/or issued through output ports. Port packets are also classified by their type, and usually port of input and output can only accept a specific set of port packet types.

To establish a port connection both input and output ports must be compatible, e.g. both ports must match exactly the port packets type they can accept. Components should be observable enough to know whether they are working correctly or not and in that case they should be controllable to make some adjustment in their internal behavior to adjust and regulate their operation. CoolBOT introduces of two kind variables as facilities in order to support control and monitoring of components:

• Observable variables; represent components features that should be of interest from outside, they are externally observable and permit publishing aspects components which are meaningful in terms of control, or just for monitoring or observability purposes.
• Controllable variables; represent components aspects which can be externally controlled, such as modified or updated. The components internal behavior can be controlled.