Stations and Capabilities

The Desigo CC software has a client-server architecture, in which a server component handles all interactions with the field networks and devices installed on the site, while the clients provide the user-facing application that operators interact with.
The computers running the various components of the Desigo CC software are referred to as stations.
In Installation, see also System Components.

Station Types

Station Types	Description	Notes
Server (required)	The computer that runs the server component of Desigo CC. It hosts all the data of the installation (the project databases) and connects to the field networks and subsystems of the building-control site. Also referred to as the Main Server.	The Desigo CC client application is also installed on the server station, so that this computer can function as an all-in-one management station. There can only be one server station. The server station can optionally host an IIS web server.
Client (optional)	An additional, separate computer on which the Desigo CC client application is installed. Also referred to as an installed client.	There can be multiple client stations, allowing multiple operators to manage and supervise the same site.
FEP (optional)	Front-end processor. An additional, separate computer that is used for load-balancing the network-based processing for a system.	There can be multiple FEP stations. The Desigo CC client application is also installed on the FEP station.
Web Server (optional)	A separate computer hosting an IIS web server component, which enables the functioning of Windows app clients. This station can be dedicated to that purpose, or it can be optionally configured to also operate as a FEP or client station.	The IIS web server can also be hosted on the server station, in which case this separate web server station is not needed.
Windows App Client	A computer used to access Desigo CC as a light application, downloaded and installed on-demand directly from the Internet Explorer browser. Once installed, it looks like the standard Desigo CC client software, but allows access to local resources only. Each time the user launches the Windows app client, a search for system updates is performed. If a new version is available, the user can choose to update it or continue to use the previous version.	For configuration instructions, in Setting Up the Project, see Setting up the Windows App Client.
Flex Client	A computer or mobile device is used to access the Desigo CC Flex Client, which can be a browser-based web app or a desktop app. It allows access to local resources only.	The web client hosting the Flex Client application can be anonymous or identified with a host certificate.

Capabilities of Different Station Types

	Desigo CC
	Server	Installed Client / FEP	Windows App Client	Flex Client
Complete access to Desigo CC resources	Yes	No	No	No
Import/export/upgrade of libraries (including object models and import rules)	Yes	No	No	No
Text localization import/export	Yes	No	No	No
Closed mode	Yes	Yes	No	Yes (desktop app only)
Request/transfer of fire panel ownership	Yes	Yes	No	Yes (identified client only)
Auto logoff due to user inactivity	Yes	Yes	No	Yes
Multiple monitor support	Yes	Yes	Yes	Yes (desktop app only)
Operator switchover	Yes	Yes	Yes	Yes
Auto logon of default user	Yes	Yes	Yes	Yes (identified client only)

Disconnection Issues in Distributed Systems

In a distributed environment, when a system connects to the others its node is automatically created in System Browser at the following path: Project > Management System > Servers.

Every system will monitor its connection status with the others and in case a system temporarily disconnects, an event is generated to inform the operator about the connection failure. When the connection is re-established, the relevant event is automatically cleared.

If a system is permanently disconnected from the others, you must manually delete the corresponding node in System Browser under Project > Management System > Servers.

Windows App Client Application Cache Issue

In installations with a high number of extension modules, especially if multi-language, Desigo CC Windows App clients might have an insufficient web application storage and fail to start (an Unknown Error displays when starting the web application).

Chromium web browser dll constrains the amount of space available for the installation of extension modules on a Desigo CC Windows App client.
Consequently, the Windows App client application cache is reduced if on the same Desigo CC Windows App client the Chromium web browser is enabled for the online help and many extension modules are installed.

To solve this issue a system administrator must enlarge the cache storage quota on the specific client computer by changing a specific registry key.

For more details, see https://msdn.microsoft.com/en-us/library/267k390a.aspx.