Public or Private Variables

About this task

A Variable ID can be a public or a private variable.

A component designer can make a Variable ID in a linked object either public or private. Using:

Variable A Screen Designer:
Public variables Can enter a value for the Variable ID in the link container, thus making some values unique to that container.
Private variables Cannot change the value for the Variable ID in the link container.

Example

The following example demonstrates configuration for a source/linked object.

  • Source object configuration
  • Linked container configuration
  • Linked object runtime test
  • Later changes

Source Object Configuration

A source object group includes the following objects.

1 Label that identifies the tank.
2 Tank that will fill based on an assigned variable value.
3 Text object that reports the runtime level.
4 Text object that reports the maximum allowed level.

Following is the configuration for the source object group.

Item Type   Name   Level Public/ Private Value assigned at the Source   Comments
Name TANKS Top level group NA TANKS TANKS is the source object name for a group that includes a tank and a label.
Variable LABEL TANKS Public No value Text object that can be changed for the linked container.
Variable FILL_LEVEL TANKS Public No value Value is a point that can be changed for the linked container. FILL_LEVEL is assigned to the:
  • Tank fill animation.
  • TANK LEVEL text.
Variable Maximum_Fill TANKS Private 15000 Value cannot be changed for the linked container. Maximum_Fill is assigned to the:
  • Tank fill animation.
  • Max FILL text.

Linked Container Configuration

Because the tank is a SmartObject, when a screen designer creates a linked object, a SmartObject Configuration dialog box opens.

The screen designer enters the following values.

Field Variable Value Description
Fill Value Public TANK101  A point that reports the actual level in TANK101.
Maximum Fill Level Private 50000 Although the field appears to be read/write, 50000 will not be the value used. The source object's private variable had been assigned the value, 15,000, which will be the value used.

Once the object is placed on the CimEdit screen, the screen designer

Procedure

  1. Opens the object's Properties - Link container dialog box.

    The Link Container tab confirms that the object is a link container.

  2. Selects the Variables tab.
  3. Enters "TANK101" for the (public) Label variable.

    Notes

    • TANK101 is already entered.
    • The variable Maximum_Fill_Level is not listed because it is a private variable and the value cannot be changed.
  4. Clicks OK to close the dialog box.

    Linked Object Runtime Test

    The following occurs when the CimView screen with the linked object opens.

    Object Value Variable Entered in the:
    1 Label "TANK101" Public Link container's Properties dialog box.
    2 Maximum Fill 15000 Private Source object's Properties dialog box.
    3 Fill Value TANK101 Public Link container's SmartObject Configuration dialog box.
    4 Fill Value TANK101 Public Link container's SmartObject Configuration dialog box.
    5 Maximum Fill 15000 Private Source object's Properties dialog box.

    Later Changes

    After the linked container was inserted on a CimEdit screen, the screen designer decided to change some source text to red.

    The linked container screen is closed and re-opened.

    The text that was changed in the source has changed to red in the link container.