Echelon Mini FX - Manual (Page 77)

64 Developing Device Applications
Introduction to Neuron C
Neuron C Version 2.2 is a programming language based on ANSI C that you can use to
develop applications for Neuron Chips and Smart Transceivers. It includes network
communication, I/O, interrupt-handling, and event-handling extensions to ANSI C,
which make it a powerful tool for the development of L
ON W ORKS device applications.
Following are a few of the extensions to the ANSI Standard C language:
• A network communication model based on functional blocks and network variables that
simplifies and promotes data sharing between like or disparate devices.
• A network configuration model based on functional blocks and configuration properties
that facilitates interoperable network configuration tools.
• A type model based on standard and user resource files expands the market for
interoperable devices by simplifying integration of devices from multiple
manufacturers.
• An extensive built-in set of I/O objects that supports the powerful I/O capabilities of
Neuron Chips and Smart Transceivers. Powerful event-driven programming extensions
based on when-tasks that provide easy handling of network, I/O, and timer events.
• Language extensions that define application interrupt handlers and use
synchronization tools, where available.
Neuron C provides a rich set of language extensions to ANSI C tailored to the unique
requirements of distributed control applications. Experienced C programmers will find
Neuron C a natural extension to the familiar ANSI C paradigm. Neuron C offers built-in
type checking and allows the programmer to generate highly efficient code for distributed
L
ON W ORKS applications.
Neuron C omits ANSI C features not required by the standard for free-standing
implementations. For example, certain standard C libraries are not part of Neuron C.
Other differences between Neuron C and ANSI C are detailed in the Neuron C
Programmer’s Guide.
This chapter provides an introduction to Neuron C. For more details on Neuron C, see
the Neuron C Programmer’s Guide.
Unique Aspects of Neuron C
Neuron C implements all the basic ANSI C types, and type conversions as necessary. In
addition to the ANSI C data constructs, Neuron C provides some unique data elements.
Network variables are fundamental to Neuron C and L
ON W ORKS applications. Network
variables are data constructs that have language and Neuron firmware support to
provide the look and feel of a regular global C variable, but with additional properties of
communicating across a L ON W ORKS network, to or from one or more other devices on
that network. The network variables make up part of the device interface for a
L ON W ORKS device.
Configuration properties are Neuron C data constructs that are another part of the device
interface. Configuration properties allow the device’s behavior to be customized using a
network tool such as the LonMaker tool or a customized plug-in created for the device.
Configuration properties provide the look and feel of a normal variable to the C program,
with the addition of controlled access by network configuration tools.