<< Click to Display Table of Contents >>   Example of Creating an ElipseX

Let's suppose a certain application needs to supervise and command 10 engines. Each engine must be represented by a drawing on a Screen, which displays a green color when operating and a red color when turned off. It must also display the engine command on the Screen, sending instructions for turning it on and off, and also displays its speed.

One possibility is to create an XControl called EngineA, with properties Status set to Boolean and Speed set to Double, according to the next figure.

1.To indicate color, engine's OverrideFillColor property must be linked to XControl's Status property, by using a Digital Link. Set the OverrideFillMode property to 2 - SolidFill.

2.To display speed, Display's Value property must be linked to XControl's Speed property.

3.The Toggle Button switches the Status property value via a Simple Link.

 

Notice that:

•Links within the library are internal, and their format is Control_Name.Property_Name

•The object, after being inserted on a Screen, must have these properties linked to real Tags, for each engine

•A Tag Link to the Status property must be performed for each EngineA

Another broader possibility is to use an XObject for the engine. Thus, all information regarding the engines remains in objects in the server. Hence, users can create several types of interface for the engine (XControls), which brings only relevant information from the server, via XObject.

Then, the EngineA object would have to be modified to point to an XObject, instead of declaring all properties on itself.

1.Create an XObject called EngineAData and declare Status and Speed properties in it.

2.Create an XControl EngineA with a single property, called MyData, of type EngineAData.

3.EngineAData must be inserted on a Data Folder in the server, corresponding to each engine. EngineA, by its turn, points to the EngineAData needed, with no need to create new Tags.

4.The Status property, linked to engine's OverrideFillCollor property, is then EngineA.MyData.Status.

5.The Speed property, linked to the Display, is then EngineA.MyData.Speed.