The Local Lon Device represents the local interface to the Lonworks network. Component-wise, it is modeled similar to any other Lon device. As a frozen slot under the LonNetwork, it always appears in the network (Figure 12). There is only one Local Lon Device—you cannot delete it or duplicate it.
Typically, (with Station as network manager), you leave LocalLonDevice properties at defaults, and do nothing else at this level in the network. The following sections provide more details:
Two properties of the Local Lon Device are unique (not in any other Lon device), as shown in its property sheet (Figure 13). Values require change from defaults only if configuring the station as a Lon node only.
These two properties are:
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External Config
By default, this is
false. If set totrue, this specifies that all Lonworks network management is performed externally, meaning that you do not use LonNetwork views like the Lon Device Manager, Lon Link Manager, and so on. -
Self Doc
String for the JACE’s (node) self documentation (if External Config is true), with a default value:
&3.0@;Niagara Server NodeUp to 1024 bytes are permitted. Note that a single asterisk (*) omits self documentation.
Whenever using self documentation, the leading header portion (&3.0@) should always be retained, along with an additional zero (0), plus other characters as described in the next section, LNS device self-documentation notes. Also see Notes when configuring as Lon node for related details.
For LNS compatibility, in the Local Lon Device’s “Self Doc” property value, you must either:
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simply enter a single asterisk (*) to omit device self documentation, or
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enter a self documentation string that includes all LonMark objects used in the station, using the following format:
&3.0@0NodeObjectName,FunctionalBlock;selfDocTextwhere, from (left-to-right):
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&character denotes an interoperable device. -
3.0identifies the major and minor version of LonWorks Interoperablility Guidelines used. -
@is used as a separator. -
0 is the first of the indices of the corresponding functional block index (0, 1, 2, etc.), where the Node object must be the first of the indices (0).
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NodeObjectNameis the description of the Node object. -
FunctionalBlockincludes any other LonMark or non-LonMark functional profiles that you wish to add to the station database. -
SelfDocTextis any text that you might want to add to describes the functional profiles.
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For example:
&3.0@0NodeObject;NiagaraAX Server Node
For LNS compatibility, the Node object represented by the LocalLonDevice also requires two mandatory network variables: SNVT_obj_request and SNVT_obj_status. You must create these network variables using the LocalLonDevice’s Local NV Manager view. See Local Nvs required by LNS for details.
Upon first execution (if Neuron Id is 0), the following sequence occurs:
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Address is set to default: channel Id 1, subnet node 1/127.
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DeviceData is filled in from local neuron: Neuron Id, Address Count, Two Domains.
Upon station startup, the following occurs:
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Updates to domain table, address table, and device state per station database.
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Program Id is set.
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Executes ping.
As shown in Figure 14, the default view of the Local Lon Device is the Local Nv Manager. This view is unique to the Local Lon Device (note that the standard Lon device views are not available).
In typical operation, the station acts as the Lonworks network manager—you do not use this view (or methods) to share Niagara data among other Lon devices. Instead, you create Lon proxy points under Lon devices, as needed,
and then link the proxy points into station logic.
However, if configuring the station as only another “Lon node,” this view lets you create “custom” Lonworks network variables (nvis, nvos, ncis) available externally to other Lonworks devices. The station appears as a “peer” Lonworks device. In this scenario, Lonworks network management is not handled by the station. For further details about configuring a station in this manner, see Notes when configuring as Lon node.Notes when configuring as Lon node
By default, the Local Lon Device has five available actions, with right-click menu access from the LonNetwork wire sheet, LocalLonDevice property sheet, Nav side bar (see Figure 15).
These are similar to other Lon device actions, and include the following:
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Ping
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Upload
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Download
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Reset
The Service Pin action is unique to the LocalLonDevice, and is useful if installing the JACE using an external Lonworks network management tool (station as a Lon node only). This action issues a Lonworks service pin message for the JACE node.
In general, you should not invoke actions on the LocalLonDevice, except a Service Pin (as described in the scenario above).