Echelon NodeBuilder FX User Manual
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Defining Device Interfaces and Creating their Neuron C Framework
3. In the Name property, enter a name for the network variable as it will appear in the LonMaker tool
and other network management tools. This name must be unique to the device, can contain up to
16 alphanumeric characters, and must start with a letter. The name cannot contain spaces or the
following characters: \ / : * ? “ < > |. The default name is nvValue.
4. If your device has a changeable interface (it has network variables with changeable types, or it
supports dynamic network variables), you can select the Has Changeable Interface check box so
that network integrators can change the network variable’s type. This option is only available if
you selected the Has Changeable Interface check box when defining the device’s program ID in
the Standard Program ID Calculator (see Specifying the Program ID in Chapter 5 for more
information). This check box is cleared by default.
Selecting this option lets you create a network variable that can send or receive different kinds of
information, depending on how the device is used. For example, you can implement a generic
PID controller device using a SNVT_temp_f as the initial type, and then let a network integrator
change the SNVT_temp_f network variable to a range of other types so that the PID controller
can control light, pressure, or other types.
5. In the Select Resource Type box, select whether the network variable you are adding is based on
a Standard or User-Defined type. If you select a User-Defined type, select the Scope of the
functional profile containing the network variable type. To use a User-Defined type, you must
first add the resource file containing the UNVT to the resource catalog as described in the
NodeBuilder Resource Editor User’s Guide.
6. In the SNVT or UNVT property, select the network variable to be added to the functional block or
device from the list.
If you are selecting a UNVT, the list contains all the UNVTs in resource files of the scope
specified in the Scope field that match the program ID template to the degree specified by the
scope. The network variable’s type must have a scope that is equal to or lower then the scope of
the functional profile upon which the functional block is based.
7. In the Direction property, select whether you are adding an Input or Output network variable.
8. If you are creating an Output network variable, select the messaging service type to be used for
transmitting updates for this output network variable in the Service Type box. You have four
choices: Unspecified, Acknowledged, Unacknowledged, or Repeated. See Editing Mandatory
Network Variables earlier in this chapter for more information about these different service types.
9. If you are creating an Output network variable, you can make the output network variable
Synchronized or Polled in the Modifiers box. See Editing Mandatory Network Variables earlier
in this chapter for more information about these modifiers.
10. Optionally, in the Self-Documentation (sd_string) property, you can enter comments to be
appended to the self-documentation string for this network variable. Network variable members
of functional blocks use a standard self-documentation format that is detailed in the . The Neuron C Compiler automatically generates
all required self-documentation information. This property can be used to provide additional notes
that can be accessed from a network tool.
11. Optionally, in the Initializer property, you can set the value for the network variable when the
device is reset. If this network variable is a structure, enumeration, or float, click the box to the
right to open the Edit Initializer dialog and enter the value or values. See Setting Initial Values
for Network Variables and Configuration Properties later in this chapter for more information.
12. Click OK. The implementation-specific network variable is added to the
Implementation-specific NVs folder.
Adding Implementation-specific Configuration Properties
You can add a configuration property to a functional block or device that is not defined by the
functional profile. This is called an implementation-specific configuration property.