Setting up variables for network components
As with other Lon devices, Lon network components communicate over the Lon network using variables. Variables are the entities
that carry information from an output to an input.
Prerequisites: You are configuring the Local Lon Device under the LonNetwork.
- Double-click the Local Lon Device in the Nav tree.The Local Nv Manager view opens.
- To create a variable click the New button.The New variable window opens.
Two variables are available for local Lon devices. Local Nv stands for Local Network Variable. Local Nci stands for Local Network configurable input.
- Select the type of variable from the drop-down list, the number to add, and click OK.A second New window opens.
- Replace the default name (for example, LocalNv) with a unique name for each variable.You change default names (
LocalNvn orLocalNcin) to a unique name using a prefix, such as nvi (network variable input) and nvo (network variable output) followed by text, which identifies the type of information. For example: nviSetpointA, nvoUnitStatusA, nciOffsetB, and so on. - Select a SNVT (Standard Network Variable Type) from the drop-down list.An alternate way to configure a variable type is to define a UNVT (User Network Variable Type) in a Lon Xml file and associate it with the variable.
- Do one of the following:
- To omit self documentation, enter an asterisk (*) for
Self Doc. - To specify self documentation, enter a text string for
Self Docthat adheres to this syntax: @fbIndex|memberNum;text, where:- @ denotes the start of nv self documentation.
- fbIndex is the functional block index.
- | (pipe) is the functional profile separator.
- memberNum is the member number within the functional block.
- text is optional text for describing the network variable.
By convention this syntax conforms to: nviSomething or nvoSomething
NOTE: A value other than asterisk (*) and that uses the syntax above is required in theSelf Docproperty of the two required network variables: nviObjRequest and nvoObjStatus.
- To omit self documentation, enter an asterisk (*) for
Below are two common
Self Doc property values for the two required node object nvs:
- nviObjRequest
Self Doc= @0|1;nviRequest - nvoObjStatus
Self Doc= @0|2;nvoStatus
After creating the two required nvs, you can continue defining/adding other local nvs and ncis. Optionally, you can also add
Self Doc strings to other local nvs and ncis, and also edit the Self Doc string for the Local Lon Device.
To omit self documentation (for any items except the two Node object 0 nvs described above), enter a single asterisk (*) in
the Self Doc property.