PLEX (programming language)
Encyclopedia
PLEX is a special-purpose, pseudo-parallel and event-driven real-time programming language
. Dedicated for AXE telephone exchange
s, it was developed by Göran Hemdahl at Ericsson
. Originally designed in the 1970s, it has been continuously evolving since then. The language has two variants: Plex-C used for the AXE Central Processor (CP) and Plex-M used for Extension Module Regional Processors (EMRP).
Several precompilers or code generators exist, to produce source code in Plex-C from higher level
languages or graphical models. These can generate Plex-C from:
Source code in Plex-C is compiled into the assembly language ASA210C.
The binary form of ASA210C is either interpreted by a combination of hardware and microcode, or is compiled by a Just-In-Time compiler into native machine code for a high-capacity microprocessor.
Code execution is triggered by specific events, encoded as signals.
An example input string that has been designed for the LI3 (P83-P90) version of the AXE Switch could be STDEP:DEV=LI3-101&&-107; this would print to the users console the current device status (busy, idle, blocked, etc)
Programming language
A programming language is an artificial language designed to communicate instructions to a machine, particularly a computer. Programming languages can be used to create programs that control the behavior of a machine and/or to express algorithms precisely....
. Dedicated for AXE telephone exchange
AXE telephone exchange
The AXE telephone exchange is a product line of circuit switched digital telephone exchanges manufactured by Ericsson, a Swedish telecom company. It was developed in 1974 by Ellemtel, a research and development subsidiary of Ericsson and Televerket.. The first system was deployed in 1976...
s, it was developed by Göran Hemdahl at Ericsson
Ericsson
Ericsson , one of Sweden's largest companies, is a provider of telecommunication and data communication systems, and related services, covering a range of technologies, including especially mobile networks...
. Originally designed in the 1970s, it has been continuously evolving since then. The language has two variants: Plex-C used for the AXE Central Processor (CP) and Plex-M used for Extension Module Regional Processors (EMRP).
Several precompilers or code generators exist, to produce source code in Plex-C from higher level
High-level programming language
A high-level programming language is a programming language with strong abstraction from the details of the computer. In comparison to low-level programming languages, it may use natural language elements, be easier to use, or be from the specification of the program, making the process of...
languages or graphical models. These can generate Plex-C from:
- Specification and Description LanguageSpecification and Description LanguageSpecification and Description Language is a specification language targeted at the unambiguous specification and description of the behaviour of reactive and distributed systems.- Overview :It is defined by the ITU-T...
graphical representation (SDL/GR) - Plex-SQL, an extension of Plex-C with databaseDatabaseA database is an organized collection of data for one or more purposes, usually in digital form. The data are typically organized to model relevant aspects of reality , in a way that supports processes requiring this information...
facilities - High Level Plex (HLPLEX) another extension of Plex-C
Source code in Plex-C is compiled into the assembly language ASA210C.
The binary form of ASA210C is either interpreted by a combination of hardware and microcode, or is compiled by a Just-In-Time compiler into native machine code for a high-capacity microprocessor.
Code execution is triggered by specific events, encoded as signals.
An example input string that has been designed for the LI3 (P83-P90) version of the AXE Switch could be STDEP:DEV=LI3-101&&-107; this would print to the users console the current device status (busy, idle, blocked, etc)