Interfacing Overview ¶

27 April 2015

This chapter provides a high-level overview of how to use and extend the external interfaces of the PLEXIL Executive.

Overview ¶

The PLEXIL Application Framework provides a flexible mechanism for adding external interfaces to the PLEXIL Executive, and to applications built on the PLEXIL Application Framework.

PLEXIL Executive facilities ¶

These artifacts are required to enable interaction between the PLEXIL Executive and an external system or environment:

One or more shared library files which implement interface adapters and/or exec listeners (C++ code).
An interface configuration file describing the adapters and listeners to be used.

Standard Interfaces ¶

The PLEXIL distribution comes with several standard interface adapters and exec listeners; see Standard Libraries for a summary.

Configuration File ¶

See Interface Configuration File for details.

Custom Interfaces ¶

For an overview of developing your own custom adapters and listeners, please see Implementing Custom Interfaces.

Writing Your Own Application ¶

In some applications, the user may prefer an executable which has all interfaces pre-loaded. In other situations, the operating system and/or build toolchain may not support dynamic loading of interface libraries. Or maybe the application requires that the executive run under the control of a real-time OS, in a particular threading enviroment.

In situations like these, it is straightforward to build a dedicated C++ executable which does exactly what the application requires. The process is outlined in Implementing Custom PLEXIL Applications.