signal definition (Z.100)

Concrete textual grammar

<signal definition>::=
signal
<signal definition item>
{,<signal definition item>}* <end>

<signal definition item> ::=
<signal name>
[<formal context parameters>]
[<specialization>]
[<sort list>][<signal refinement>]

<sort list> ::=
(<sort> {, <sort>}*)

<formal context parameter> in <formal context parameters> must be a <sort context parameter>. The <base type> as part of <specialization> must be a <signal identifier>.

Semantics

A signal instance is a flow of information between processes, and is an instantiation of a signal type defined by a signal definition. A signal instance can be sent by either the environment or a process and is always directed to either a process or the environment. A signal instance is created when an Output-node is interpreted and ceases to exist, when an Input-node is interpreted.