Echelon LonMaker - Manual (Page 129)

LonMaker User’s Guide 113
Instead of performing steps 1 and 2, you can hold down CTRL and drag the subsystem or
supernode shape to the desired location.
3. Enter the information for the new subsystem following the instructions in Creating a Subsystem.
4. Click Finish. The LonMaker tool copies the subsystem or supernode. If only a single end of a
reference connection is in a copied subsystem, the network variable will be connected to the
existing connection specified by the reference. The copy operation does not require any user
input, with the following exceptions:
• The LonMaker tool prompts you to determine whether copied channel shapes represent an
existing channel or a new channel.
• If the copy causes functional blocks to be created that are not associated with any device, the
LonMaker tool prompts you to determine on which devices the new functional blocks reside.
Creating Connections
Creating connections enables devices to exchange data. You can create unicast connections in which
an output network variable is connected to a compatible input network variable, and you can create
multicast connections in which a single output or input network variable is connected to multiple
compatible input or output network variables, respectively. Network variables must have the same
type to be compatible. Once you create a connection, the input network variables will receive all
updates from the output network variables in the connection. You can also connect input and output
message tags, and the input message tags will receive all updates from the output message tags in the
connection. This process of connecting network variables and message tags is called binding, and the
logical connections are thought of as virtual wires.
You can connect a network variable on any functional block or supernode in a network with a
compatible network variable on any other functional block or supernode—even if the network
variables are in different subsystems. You can also create a connection between input and output
network variables on the same functional block. This is called a turnaround connection. A turnaround
connection may be appropriate for a device that receives the data it transmits.
Every connection has one hub network variable and one or more target network variables. The end of
the hub network variable is marked with an x; the target network variables are each marked with a +.
When creating a unicast connection, it does not matter which end of the connection is the hub and
which is the target. However, when creating large multicast fan-in connections (multiple output
network variables connected to a single input network variable) or fan-out connections (a single output
network variable connected to multiple input network variables), make the common network variable
the hub. This will reduce the time required to make the connection. For example, in a fan-in
connection, the single input network variable should be the hub; in a fan-out connection, the single
output network variable should be the hub.
You can connect functional blocks in three ways:
• Use the Connector shape on the LonMaker Basic Shapes stencil.
• Use the Connector tool on the Visio Standard toolbar. This is the easiest way to create unicast
connections.
• Use the Network Variable Connection dialog box. This is the easiest way to create multicast
connections.
The following subsections explain how to use each of these three methods.