Network Variable Output

The Network Variable Output (NVO) converts input value(s) (Public Variable(s)) into a raw network variable output that is published onto the LonWorks network. Each NVO can be defined with up to 16 fields.

Note: The maximum limit of the fields is based on the memory limitation of a selected controller model and NV size cannot exceed 31 bytes.

Each field is converted from Internal Data Type to Network Data Type engineering units. Internal data type is the units of the input of the Network Variable. Network Data Type is the engineering unit sent by the Honeywell Spyder controller onto the LonWorks network. For example, programming the Network Data Type to be SNVT_temp_p, and the Internal Data Type to be DegF converts network temperatures of type SNVT_temp_p into DegF for use by the Function Blocks.

Adding an NVO

You can add an NVO from:

  1. NV Configuration View
  2. HoneywellSpyder Palette

Adding an NVO from the NV Configuration View

To add a new Network Variable Output:

  1. Browse to Station > Config > Drivers > LonNetwork > LonSpyder.
  2. Select ControlProgram > Views > NV Configuration View. The summary page appears with a list of pre-programmed Mandatory, Fixed, and Custom NVs.

Note: If adding an NVO to a Application, browse through to the appropriate Application on the Nav palette.

  1. Click Add NV. The New NV dialog box appears.
  2. Select Network Variable Output.
  3. Click OK. The Add NVO dialog box appears.
  4. Fill the necessary information in the fields and click OK to complete adding an NVO. The NVO is displayed in the NVs table.

Note: You cannot add a Software Output to a macro.

Name Definition
NVName The name that you can configure this NVO with.
Output Refresh Set the Output Refresh of each NVO to either Polled or Unpolled. 
  • Output Refresh is only valid when the Guaranteed Periodic Refresh is set to False. 
  • If a Output Refresh is Polled, then the value of the output network variable is never propagated as a result of its value changing.  Instead the value of the output network variable is sent only in response to a poll request from a reader node.
Guaranteed Periodic Refresh Set Guaranteed Periodic Refresh of each Network Variable Output to either True or False.
  • True indicates that the Honeywell Spyder controller periodically sends this variable to the LonWorks network at the GPU rate (nciSndHrtBt). Setting this to True also enables the Significant Event Notification also known as SEN Delta. The Network Variable is also sent on the LonWorks Network whenever any field exceeds the SEN Delta. SEN Delta of zero (0) disables the feature.
  • False indicates that the Honeywell Spyder controller does not send the value to the LonWorks network. The Network Variable Output must be polled to get its value.
Message Service The Message Service type of each NVO is Unacknowledged, Acknowledged or Unacknowledged Repeated.
  • Unacknowledged means the update is sent once and no acknowledgement is expected.
  • Acknowledged means all receiver nodes must acknowledge receipt of the message to the sender node.
  • Unacknowledged Repeated means the update is sent multiple times and no acknowledgements are expected.
Copy From Enables you to select Standard NVs or User Defined NVs.
Standard If you select Standard you can choose a list of available NVs from the Select list. Standard NVs are pre-defined NVs known as SNVTs.
Custom You have two options to select Custom NVs from:
  • File: Enables you to select a custom NV that was created and saved regardless of the Station or device. Click the File option and click the Browse button; navigate to and select the .bog file. From the Select Type list, select the custom NV within the .bog file (a single .bog file may contain multiple custom NVs).
  • Station: Enables you to select a custom NV that was created and saved only within any device belonging to the same Station. Click the Station option and select the device where the custom NV was created and saved. From the Select Type list, select the custom NV you are looking for.
.
Fields Properties Displays the following properties for each field:
  • Field Name
  • Data Category
  • Internal Data Type
  • Network Data Type
  • Significant Event Notification
Add Field Use this button to add a field. You can define a maximum of 16 fields.
Delete Field Use this button to delete a field.
Edit Selected Field  
Field Name User defined field name.
Data Category Select the data type for the NV fields.
Internal Data Type It is the unit(s) of the output of the Network Variable. Specify the Internal Data Type. Based on data category selected, the drop-down list changes.
Network Data Type It is the engineering unit received by the Honeywell Spyder controller. Specify the Network Data Type. Based on data category selected, the drop-down list changes.
Significant Event Notification Indicates the sen delta value of the selected variable.You can edit this field. The units are based on the Network Data Type selected.
UNVT Name Enter UNVT Name in case you are creating a new NVO.
Export to File When creating custom UNVTs, use this option to save it to a .bog file so it can be reused. A single .bog file may contain multiple custom NVs.
>> Click this button to view the network/internal data type details.

Click this button to view the Facets Details Viewer for the network/internal data type.

The following information is displayed:

  • Minimum – The minimum limit for selected unit
  • Maximum– The maximum limit for selected unit

OR

  • Range - Indicates the possible enumeration with their ordinal for a selected unit.
  • Units - Indicates the units symbol for the selected unit (If it shows null, it means the unit symbol is not applicable there )
  • Type - Indicates the data type size for selected unit
  • F32 - 4 Bytes
  • U16 – Unsigned 2 bytes
  • S16 – Signed 2 bytes
  • U8 – Unsigned byte
  • S8 – Signed byte
  • E8 - Enumerated byte
  • UB – Unsigned bit
  • Resolution - Scaling factor for the selected Unit. When a value is written to controller, the value is divided by the value specified in the Resolution field and when it is read from the controller, it is multiplied by the Resolution value before it is displayed in Niagara.
  • Precision - Precision for the selected Unit

Note: You can create new NVs even if the NV count, field count, or unit stores count has been exceeded. Honeywell Spyder displays a message informing the same but allows creation of NVs.

Exposing an NVO from the NV Configuration View

To expose the NV fields you have added:

  1. Expand the NVO in the table to display the fields. Select the fields you want to display on the wiresheet and click the Show on wiresheet as Points button
    or
    Drag the fields you want to display on the wiresheet on to Software Points available on wiresheet list at the bottom of the wire sheet. The Add Points dialog box appears.
  2. Click OK. The fields you have selected appear on the Software Points available on wiresheet list at the bottom of the wire sheet. The field name displays the NV Name. Field Name information. If you do not select point to be displayed on the wiresheet, the NV is added but is not visible on the wiresheet.
  3. Click Cancel if you do not wish to continue adding an NVI.

Adding an NVO from the Spyder Palette

While in the midst of creating an ControlProgram/Application, if you need to quickly add an NVO, use the Software Outputs item on the Spyder Palette.

Note: You cannot add an NVO or a Software Output point to a macro.

To add an NVO to an ControlProgram/Application:

  1. On the Spyder Palette, expand the SoftwarePoints folder. If the Spyder Palette is not visible on the left side of your screen, on the Menu bar, click Windows > Sidebars > Palette to display the Palette.
  2. Drag a Software Output to the wiresheet of an ControlProgram/Application. The Name dialog box appears.
  3. Type a name for the point and click OK.
  4. Right-click the Software Output point you have just added and select Configure Properties. The Configure Properties dialog box appears.
  5. Type/select the following:
  1. Click OK to complete adding an NVO.

Note: When you create an NV using the Spyder Palette on the wiresheet, by default, the fields are exposed and you do not have to manually expose the fields of the NVO on the wiresheet.

Connecting NVOs

Once you have created an NVO, you can connect an NVO to an NVI/Function Block or Physical point by left-clicking on the output of an NVI/Function Block/Physical point and dragging your mouse to the input of an NVO.

Grouping as NVOs

You can group (share) two or more NVO points, or valid/invalid software output points to:

When grouping to create a new NVO, the number of fields of the new NVO equals the number of software output points selected for grouping. When you group points to add to an existing NVO, the selected software output points are added to the existing fields of the selected target NVO. In either case, the structure of the source NVOs to which the points originally belong are not affected. The new/edited NV appears in the upper pane in the list of NVOs in the NV Configuration View. The lower pane in the NV Configuration View displays the list of all NVOs to which a particular software output has been grouped into.

Note

The following table summarizes how you can group a point(s) of a source NV to form a target NV.

Source NV Points Target NV
NVI NCI NVO Valid Software Input Point Invalid Software Input point Software Input Point  configured as Constant Valid Software Output Point Invalid Software Output point
NVI Yes Yes No Yes Yes Yes No No
NCI Yes Yes No Yes Yes Yes No No
Valid Software Input Point Yes Yes No Yes Yes Yes No No
Invalid Software Input point Yes Yes No Yes Yes Yes No No
Software Input Point  configured as Constant Yes Yes No Yes Yes Yes No No
NVO No No Yes No No No Yes Yes

To group points of NVOs:

  1. On the NV Configuration View, select the points of one or more NVOs that you want to group from the Software points available on wiresheet list.

Note: Use the CTRL key on your keyboard to select the different points you want to group.

  1. Click the Group as NV button. The Group as NV dialog box appears.
  2. Fill the necessary information in the fields as explained in the following table.
Name Definition
Group as New NV Select this option if you want to save the points you want to group as a new NVO. In this case, you can enter a new NVO Name.

Note: The new NVO is created on the same folder on which the NV Configuration View is invoked. Example: If you have a ControlProgram which has an Application2 residing in Application1, if you group points on the NV Configuration View of Application2, the new NVO is created in the Application2 folder. However, if you grouped NVs on the NV Configuration View of the Application1, the new NVO is created in the Application1 folder.

Add to Existing NV Select this option if you want to add the points you want to group to an existing NVO. In this case, you can select an existing custom NVO from the NV Name list.

On selecting this option, the original fields of the NVO to which the new points are added are listed in the Fields Properties table.

Note: In the case where the selected NVO was of a SNVT type, the NV is converted to a UNVT after grouping of points is done

NV Name The name that you can configure this NV with.
NV Type The NVO type you want to save the selected points for grouping as.
Fields Properties Displays the following properties for each field:
  • Field Name
  • Data Category
  • Network Data Type
  • Internal Data Type
Up Arrow Use this button to reorder a field and move it up in the list.
Down Arrow Use this button to reorder a field and move it down in the list.
Point Name The name of the point. It is in the format NVName_PointName.
Field Name User defined field name.
Data Category The non-editable data type for the NV fields.
Network Data Type It is the engineering unit received by the Honeywell Spyder controller. This is non-editable.
Internal Data Type It is the unit(s) of the output of the Network Variable. This is non-editable.
UNVT Name Enter UNVT Name in case you are creating a new NVO.
  1. Click OK. The new NVO is created and appears in the NVs list in the NV Configuration View. If you select Add to an existing NV, the fields are added to the existing NVO and can be seen in the NVs list.