Network Variable Input

The Network Variable Input (NVI) converts a raw network variable input into a value(s) that can be used by other function blocks.

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 Network Data Type to Internal Data Type engineering units. Network Data Type is the engineering unit received by the Honeywell Spyder controller. Internal Data Type is the unit(s) of the output of the Network Variable.

Example: Programming the Network Data Type to be SNVTtempp, and the Internal Data Type to be DegF, converts network temperatures of type SNVTtempp into DegF for use by the Function Blocks.

Adding an NVI

You can add an NVI from:

  1. NV Configuration View
  2. HoneywellSpyder Palette

Adding an NVI from the NV Configuration View

To add a new Network Variable Input:

  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 NVI to an application, browse through to the appropriate application on the Nav palette.

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

Note: You cannot add an NVI to a macro. You can only add a Software Input with Point Type as Constant to a macro.

You cannot add a Software Output to a macro.

Name Definition
NVName The name that you can configure this NVI with.
Fail Detect Set the Fail Detect of each NVI to either True or False. 
  • True means if the Network Variable Input is bound and it has not received an update from the Lon network source in the fail detect time then an alarm is generated and the Network Variable Input is set to Invalid.
  • False means the Network Variable Input retains what was written to it until a Lon network source changes it or the Honeywell Spyder has a power outage or resets.
Copy From Enables you to select Standard NVs or User Defined NVs (NVs you have created and saved earlier).
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 If you select Custom you can choose a list of available NVs from the Select list. NVs you have created. This is taken from UNVT Name field.
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
  • Network Data Type
  • Internal Data Type
Add Field Use this button to add a field. You can add a maximum of 99 fields.
Delete Field Use this button to delete a selected field.
Edit Selected Field  
Field Name User defined field name.
Data Category Select the data type for the NV fields.
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.
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.
UNVT Name Enter UNVT Name in case you are creating a new NVI.
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 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 NVI Field From NV Configuration View

To expose the NV fields you have added:

  1. Expand the NVI 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 wiresheet. 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 your screen on the right side. 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 NVI From Spyder Palette

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

Note: You cannot add an NVI to a macro. You can only add a Software Input with Point Type as Constant to a macro.

To add an NVI 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 Input 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 Input point you have just added and select Configure Properties. The Configure Properties dialog box appears.
  5. Select Software Input from the Point Type field.
  6. Type or select the following:

Note: If the Point Type is Constant and the Share Point on Network option is checked, this NV behaves as an NCI.

  1. Click OK to complete adding an NVI.

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 NVI on the wiresheet.

Connecting NVIs

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

You can group multiple points spread across NVs into a single new NV or add it to an existing one. The points must be available on the wiresheet to make such a grouping possible. Multiple points of an NV of the type NVI and NCI can be grouped together to create a new NV. The new NV created can be saved as an NVI or NCI. When one or more NVs are grouped 

Also, invalid points can be grouped with fields of another NV to create a new  NV.

You can also group a single point belonging to an NV. In this case a new NV is created.  

Note: The Group as NV option is not available for software points of type:

Grouping Points of type NVI

You can group two or more points of type NVI, NCI, valid software input point, invalid software input point, or software input point configured as constant to:

When grouping to create a new NVI/NCI, the number of fields of the new NVI equals the number of software points selected for grouping. When you group points to add to an existing NVI/NCI, the selected software output points are added to the existing fields of the selected target NVI/NCI. The new/edited NVI/NCI appears in the upper pane in the list of NVs in the NV Configuration View. The lower pane in the NV Configuration View displays the list of all NVs with which a particular software output has been grouped.

The result of such a grouping is that the previous NVI/NCI is modified such that the corresponding field to this point is removed from the NV. The NV is deleted if the NV was a single field NV.  This happens when points selected are already attached to an existing NV.

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 NVIs:

  1. On the NV Configuration View, select the fields 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 fields you want to group.

  1. Click the Group as NV button. The Confirmation dialog box appears. The fields are deleted from the NVs from which they are being selected.
    If you select a field from an NV (for grouping) in which it was the only field, the NV from which it is being selected is deleted.
  2. A message appears warning you that if the selected point is attached to an NV, grouping deletes that point from that NV. Click OK. The Group as NV dialog box appears.
  3. 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 selected fields you want to group as a new NV. In this case, you can enter a new NV Name.

Note: The new NV is created on the same folder in 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 NV is created in the Application2 folder. However, if you grouped NVs on the NV Configuration View of the Application1, the new NV 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 NV. In this case, you can select an existing custom NVI/NCI from the NV Name list.

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

Note: In this case, the selected existing NV is edited to reflect the changes.

Note: In the case where the selected NVI 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 NV type you want to save the selected fields as. You can choose NVI or NCI.
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.
Field Name User defined field name.
Data Category Select the data type for the NV fields.
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.
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.
UNVT Name Enter UNVT Name in case you are creating a new NVI. This is not mandatory.
  1. Click OK. The new NV 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 NV and can be seen in the NVs list.