Echelon IzoT NodeBuilder - Manual (Page 188)

Introduction to Neuron C
Neuron C Version 2.3 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
IzoT Commissioning 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.
Neuron C also provides a way to organize the network variables and configuration properties in the
device into functional blocks. Functional blocks provide a collection of network variables and
configuration properties that are used together to perform one task. These network variables and
configuration properties are called the functional block members.
174 Developing Device Applications