Rockwell Automation FactoryTalk View Site Edition Users Guide - Manual (Page 128)

F ACTORY T ALK V IEW S ITE E DITION U SER ’ S G UIDE
6–6
• •
•
•
•
The HMI project is loaded by the HMI server, either when the first client connects to the
server, or when the operating system initializes. For more information, see “Choosing
how the server starts” on page 6-16.
HMI clients
HMI clients are software programs that obtain information from, or write information to
HMI servers or data servers. FactoryTalk View Studio, the FactoryTalk View SE
Administration Console, and the FactoryTalk View SE Client are all HMI clients.
Areas
All FactoryTalk View applications have one system-defined area called the application
root area, which has the same name as the application. The application root area can
contain one HMI server, and one or more data servers.
In a network distributed application, you can create additional areas to divide the
application into manageable, logical parts, or to organize it in a way that makes sense for
the process it is controlling.
For example, an area might represent a portion of a process, or a region within the process
facility. An automotive plant could be divided into areas called Press and Fabrication,
Body Shop, Paint Shop, Engine, and Transmission; a bakery could be divided into areas
called Ingredients, Mixing, Baking, and Packaging.
Alternatively, a plant with identical production lines could be divided into areas called
Line 1, Line 2, Line 3, and so on. To add a new production line to the application, you
could create a new area, and then copy the identical HMI server project into the area.
Each area you add to a network distributed application can contain one or more sub-areas,
and one or more data servers. Each area or sub-area can contain only one HMI server.
An area or sub-area can contain multiple data and alarm servers, but it is best practice for
each area to contain only a single data or alarm server.
About the home area
In a network distributed application, the area that contains a given application component,
such as a graphic display, is called the home area.
When you refer to an application component without specifying the area, FactoryTalk
View SE uses the home area to locate the component.
For example, if an object in a graphic display refers to a tag without specifying an area,
FactoryTalk View assumes that the tag and the display are in the same home area.
If the tag cannot be found in an HMI server or a data server in the display’s home area, an
error is logged when the display is run.