2 Visual Components Manuals

3.5 Software Modules on the Controller
Runtime system resources consist of .BR modules. These modules contain executable code for the drivers and
Visual Components Runtime (command interpreter). They also contain compiled byte code of the Visual
Components editor project, including the necessary resource files.
All required modules are automatically inserted by the project manager. The following is a list of individual
modules including some examples provided for better understanding.
3.5.1 Executable Visual Components Modules
Introduction to Visual Components 2.3
The Visual Components runtime environment is divided into code and data objects. This section discusses
executable modules in .BR format.
There are many specialized modules due to the various platforms (CPU types), displays, and panel units.
When a new project is created, the most recent versions of executable .BR modules are automatically
transferred to the project. Different modules are used depending on the project and hardware.
Modules are automatically transferred to the target system when the project is downloaded.
All Visual Components runtime modules are tied to the system as non−cyclic tasks with lower priority than cyclic
tasks. Cyclic user tasks (task classes) are therefore not influenced by runtime performance. Visual Components
runtime modules run in the system idle time with low priority.
A simple and clear definition of timing performance is difficult because of the different ways that application
software loads down the CPU. This is mainly due to the lower priority of Visual Components runtime modules.
If a system does not have much idle time available, then display speed and key reaction are slower on the target
system.
Example:
A cyclic task running every 10 ms requires 8ms from the CPU to complete the task. Thus, approx. 2 ms remain
on the CPU for the remaining system operations (I/O updates, system routines, communication). In the
remaining time (2 ms), Visual Components loses CPU time as well. In this example, this is less than 20%. If
20% is sufficient, then problems do not occur. If this is not sufficient, then display speed and key reaction time to
input are slow. This can cause problems for extensive pictures which have many input and output fields.
Time bottlenecks can occur for INA2000 communication (Automation Studio online connection / PVI
visualization) since it also runs during idle time, i.e. the connection to the PC (AS or PVI) can be interrupted or
206 3.5 Software Modules on the Controller