- The central part of the MatPLC; virtual backplane. Each
module plugs into this core.
- custom-made module
- A module written in the C language because none
of the generic or specific modules provided by the MatPLC were
- functional specification
- A written statement detailing what a system
- generic module
- A module that comes with the MatPLC and is used
- HMI module (or MMI module)
- A module that interacts with the
- I/O module
- A module that connects to the "real world", or sometimes
to a slave PLC over a bus or other connection.
- The operating system for which the MatPLC is
- The traditional name for the main
configuration file of the MatPLC.
- logic engine
- A module that does the actual logic, decision making
- A quality of a system where it consists of various parts
which separate cleanly and fit together well. High modularity costs some
design time but pays back well through clarity, elegance, maintainability
- A component of the MatPLC architecture. Several modules
running together make a useful MatPLC. Note that other parts of an
installation may also have modules - the machine itself, I/O hardware, the
software you write for the MatPLC, the Linux kernel, etc.
- The basic unit of storage and communication within the MatPLC.
Points may be 1-bit, corresponding to discrete inputs, outputs,
internal/memory coils, flags &c, or multi-bit (up to 32-bit),
corresponding to analog inputs, outputs, integer or floating point
registers &c. Each point has a name by which it is known throughout the
- Many modules, especially logic engines, work in a cycle. One
repeat is called a scan. It begins by obtaining a copy of all the points
from the MatPLC core. It then evaluates all the logic or does all the
calculations (depending on the module). Finally, all changed points are
written back to the MatPLC core - this only happens at the end of the
scan, so if the logic wrote a point several times with different values,
only the last value is ever seen by any other module.
- specific module
- A module that is created for a particular project
using the tools provided by the MatPLC. Unlike a generic module, it
does not directly come with the MatPLC.
$Date: 2004/12/28 05:32:09 $