Constants

A constant input is a non-physical input which is not visible to the network. You can configure Constant blocks and use them while creating application logic in BACnet Spyder.

To add and configure a network input block:

  1. Right-click ControlProgram under Honeywell Spyder in the Nav palette and select Views > Wiresheet View to view the wiresheet.
  2. Drag the Constant block from the Spyder Palette on to the wire sheet.
  3. Type the desired name for the Constant block and click OK. The block appears as a container on the wire sheet similar to any function block.
  4. Right-click the container and select Configure Properties. The Constant dialog box appears. The following table defines the fields shown in the dialog box.
Name Description
Point Name Type a name of the function block or use the default names given by the tool.
Point Type Constant is the default selection. You can select Constant, Network Input, Network Setpoint, Binary Input or Modulating Input to change the point type.
Point Category Displays the unit of measurement for the Point Type.
Unit Displays the engineering unit based on the Point Category.
Sub-Category Displays the enumeration type for the software points. The field Unit is renamed as Sub-Category if the point category selection is unitless.
Advanced Displays the BACnet object details. Object Name, Object Type, Object Instance are the fields provided. Object Name is automatically provided by the tool and can be edited. Object Instance number can also be edited. Object Type is a read only field and cannot be edited.
OK Saves the entered information and closes the dialog box.
Cancel Closes the dialog box. Any information entered is lost.

To define your own custom enumeration type for the software points:

  1. Select Custom from the Sub-Category list.
  2. Click the button next to the Sub-Category drop-down. The Enum dialog box appears.
  3. Click the check box Load from Standard list to load the range from the standard list.
    or
    Click Add to create your own custom enumeration type. Enter the New Enum name and click Save.
  4. Click OK.

Note: You can drag IOs on to the wiresheet even when all pins are used up. Honeywell Spyder allows IOs to be dropped but they are not assigned with a pin. Such IOs are termed as invalid IOs. A message indicating that the IO does not get a pin is displayed.

Note: You can add a Constant to a macro.

Point Conversion

What do I want to convert? To what do I want to convert? How do I do it? What is the effect?
Constant Network Input
  1. Right-click the Network input block and select Configure Properties.
  2. Select Constant from the Point Type list.
  3. Select a Point Category.
  4. Click OK.
  1. If the Functional block slot to which the point was connected was of type Constant/Connector, the slot is converted from Constant type to Connector but the link is retained.
  2. If the functional block slot to which the point was connected was of type Connector only, the link is broken.
  3. A network input is created and added to the Objects table in the Object Configuration View.
Constant Network Setpoint
  1. Right-click the Network input block and select Configure Properties.
  2. Select Network Setpoint from the Point Type list.
  3. Select a Point Category.
  4. Click OK.
  1. If the Functional block slot to which the point was connected was of type Constant/Connector, the slot is converted from Constant type to Connector but the link is retained.
  2. If the Functional block slot to which the point was of type Constant only, the link is broken.
  3. A new setpoint input is created and added to the Objects table in the Object Configuration View.
Constant Binary Input
  1. Right-click the Network input block and select Configure Properties.
  2. Select Binary Input from the Point Type list.
  3. Select Type.
  4. Select Data Type.
  5. Click OK.
  1. If the Functional block slot to which the point was connected was of type Constant/Connector, the slot is converted from Constant type to Connector but the link is retained.
  2. If the Functional block slot to which the point was of type Constant only, the link is broken.
  3. The resulting physical IO object (Binary input in this case) gets any free IO pin available. If no pin is available, the resulting physical IO becomes an invalid IO (IO with no pin).
Constant Modulating Input
  1. Right-click the Network input block and select Configure Properties.
  2. Select Modulating Input from the Point Type list.
  3. Select Type.
  4. Select Data Type.
  5. Click OK.
  1. If the Functional block slot to which the point was connected was of type Constant/Connector, the slot is converted from Constant type to Connector but the link is retained.
  2. If the Functional block slot to which the point was of type Constant only, the link is broken.
  3. The resulting physical IO object (Modulating input in this case) gets any free IO pin available. If no pin is available, the resulting physical IO becomes an invalid IO (IO with no pin).