Is there an object that can be use to allow nciState LON network variable bit values to be entered from the I/A Series R2 graphics?


Using a nciState Lon network variable to set operational modes of a MNL-800 application.   Needs to be able to allow these inputs to be set from the GUI.

Product Line

TAC I/A Series


MNL-800 application program

Graphical User interface built with the I/A Series (Niagara) R2 system.


Desire to allow a user at the graphical head end of the BMS system to configure the individual bits of a LON state type network variable.


The following discussion is based on the user interface engineering work being done within the WorkPlace Pro engineering tool of the I/A Series R2 system.

The "DynamicCmd" control object found in the "conversion" folder of the Lonworks jar file can be linked to a SNVT_State type Lonworks network variable. 

After linking the DynamicCmd control object to the desired controller shadow object nci type network variable, the DynamicCmd object learns the configuration information for the linked network variable.  The next step in configuring this object for this type of use is to set a name for each control bit element of the network variable.  These defined names are displayed when the GUI user clicks on the control point.  The user then selects the bit field name (from the displayed list) to command and then selects the binary value (True or False)to be written to that bit field.

The following is an example of this control logic where the dynamic device is the MNL-800 controller with the network variable nci_cmd as the input constant and nvo_stat as an output state variable that allows the display of 16 internal bit state variables.

This image shows the configured list of boolean bits that will be configurable via this DynamicCmd_1 object:

When the GUI user selects this command object, the following field list is displayed:

And after selecting the "Fan2-S/S" enable selection, the following popup window is displayed allowing the user to specify the boolean state for that command bit.  The value will be written to the controller when the [OK] button is clicked.