Nematron Pointe Controller - Manual (Page 108)

Chapter 5: Developing Controller Programs Pointe Controller User Guide
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5.1 Basic Concepts in PointeControl
The PointeControl visual framework editor (VFE) provides the tools you need to
design and compile machine control applications that can be run on Pointe
Controller hardware products.
In the framework editor, you create application projects made up of individual
components — also called “ objects — such as Flow Charts, Ladder Diagrams, and
Logic Memory tables. Each object’s properties describe instructions and attributes
for that object. The framework editor arranges these objects into an expandable
hierarchy. You build the project by adding objects to the hierarchy and defining
the object properties.
After you complete your application project, you build (compile) the project into
runtime module that can be downloaded to and run on your Pointe Controller
unit. Using the PointeControl Monitor utility (included with the PointeControl
development software), you can monitor and debug your application as it runs on
your Pointe Controller.
5.1.1 Multiple Programming Languages
PointeControl provides tools to develop programs in either Nematron’s patented
Visual Flowchart Language (VFL) or traditional Relay Ladder Logic (RLL).
You can develop programs using only Flow Charts or only Ladder Diagrams , or
you can mix the two together and use whichever language is most appropriate to
each programming task. Charts communicate with each other by reading from
and writing to variables in the
Logic Memory database. Charts never directly
reference each other.
5.1.2 Memory Allocation and Access
In traditional control logic engines, program memory is laid out in fixed data
tables and tags must be addressed as directly represented variables (DRVs).
Sometimes, the user must even manually allocate the available memory.
PointeControl does not have fixed data tables. The user defines tags and variables
as needed, using plaintext tag names (or “aliases) rather than DRVs. Tags are
organized by type in the
Logic Memory database. A broad range of types is
supported, including bit, integer, floating point, string, and timer.
The Logic Memory database is globally accessible, allowing all Flow Charts,
Ladder Diagrams, and I/O points to communicate freely and continuously with
each other using the same data in common. For example, a Flow Chart can read a
variable that was set by a Ladder Diagram, or a Flow Chart and a Ladder Diagram
can both monitor an input tag that is
associated with one of the controller’s I/O
points, and so on.
All data can be made available to the network via Modbus mapping . For more
information, see Chapter 8, “Networked Operations,” starting on page 216.