Echelon Neuron C - Manual (Page 114)

102 Using Functional Blocks to Implement a Device Interface
Overview
The device interface for a L ON W ORKS device consists of its functional blocks,
network variables, and configuration properties. A functional block is a collection
of network variables and configuration properties, used together to perform one
task. The network variables and configuration properties contained within a
functional block are called the functional block members . Using functional blocks
promotes modular device design, and focuses the integrators on the control
algorithm.
Functional blocks simplify the installation of your devices by network
integrators. Integrators are able to view your devices as collections of task-
oriented functional blocks rather than monolithic device applications. When
network integrators combine your functional blocks with other functional blocks
within a network, they can easily see the relation of the different functional
blocks within the network. For example, Figure 9 illustrates the integrator view
of a temperature controller implemented with functional blocks. The example
illustrates seven functional blocks and their network connections. These
functional blocks are actually implemented on two devices, but the figure clearly
shows how the input sensors provide data to a temperature controller that in
turn provides outputs to actuators and a process monitor.
Figure 9. Network Design with Functional Blocks
Functional blocks are defined by functional profiles . A functional profile is used
to describe common units of functional behavior. All four member categories are
optional, for example, there might be no mandatory member network variables
defined in a profile, or there might not be any optional configuration property
members defined.
Each functional profile defines mandatory and optional network variables and
configuration properties. Each functional block implements an instance of a
functional profile. A functional block must implement all of the mandatory
network variables and mandatory configuration properties defined by the
functional profile, and can implement any of the optional network variables and
optional configuration properties defined by the functional profile. A functional
block can also implement network variables and configuration properties not