Creating a visualization

In contrast to TwinCAT 2, the visualization clients simply act as interpreters of drawing commands. Regardless of its type (PLC HMI, PLC HMI Web), each client receives the same instructions, so that the resulting visualization is the same for each type. The consequence of this is that the associated visualization application always has to be downloaded to the PLC. This may represent a problem for small controllers.

A distinction is made between three different visualization variants in the PLC project:

  • Integrated visualization – visualization runs in the development environment of TwinCAT on the programming system
  • PLC HMI – visualization runs without development environment on the control computer or a third computer
  • PLC HMI Web – visualization runs in a browser

Despite the three different variants, engineering is necessary only once, as a result of which the look and feel is identical in all visualizations. PLC HMI and PLC HMI Web can be enabled by simply adding TargetVisualization and WebVisualization objects. The availabilities of the individual Visualization elements and functions in the different variants can be found in the section "Availability"

A visualization can consist of several visualization pages. Each of these pages is managed in a visualization object. In the settings of a visualization object it is possible to change the size and the intended use ("Visualization", "Numpad/Keypad", "Dialog"), for example. When the first visualization page is added, the visualization libraries and a Visualization Manager, which is used for managing general settings for all visualization pages of a PLC project, are automatically added.

A visualization page is developed in a Visualization Editor. This editor is supplemented by a Toolbox, which provides the available visualization elements, and a Properties window for configuring the added elements. The visualization elements are provided by the visualization libraries, based on the currently selected profile. The visualization elements can be arranged and grouped conveniently as required.

In contrast to TwinCAT 2, all visualization elements and the visualization objects themselves are implemented as IEC61131-3 function blocks. They can be saved in libraries and thus be made available in other projects. Moreover, the visualization pages managed in the visualization objects can be instantiated, i.e. referenced, in other visualization pages. This concept is complemented by placeholders in the form of inputs and outputs, through which the referenced pages can be configured. The placeholders can be edited in an interface editor. In this way it is possible to develop default pages or dialogs in a one-time effort for subsequent unlimited reuse with different parameterizations.

The visualization elements can be animated via project variables, which can be entered in the corresponding settings, either directly or via expressions, i.e. combinations of the variables with operators and constants. This enables scaling of variable values, for example, to make them suitable for application in the visualization. Elements of type rectangle can thus be programmed for an absolute movement, for example.

In addition a user administration and a language selection, based on text lists, can be implemented. ANSI and Unicode are available as character encoding variants in the visualization. Within a visualization it is also possible to use any expressions, even function calls.

TwinCAT 2 visualizations can be imported.