Architecture

The basic architecture displayed in the figure below gives an overview for the involved WinCC OA managers or software modules for the WinCC OA ULC UX.

Figure 1. ULC UX Architecture

When a browser tries to connect to the ULC UX - URL of the WinCC OA HTTP Server, the HTTP server returns the ULC UX web page and automatically starts a local WinCC OA UI manager. This server side UI manger transfers displayed information of the UI into HTML 5 interpretable data chunks.. A Java Script library at Client side afterwards interprets those data chunks and draws the graphics in the browser.

Please note that for implementing the schematic overview from above the config entry [httpServer] uiUsesMainServerAsFileServer = 0 must be set inside of the config file of the HTTP Server as well as all WinCC OA project files (panels, scripts, etc.) must be available inside of the http server project.

Alternatively a separate web server can be started on the WinCC OA server and the ports 5678 (default port Multiplexing Proxy) and 443 (default port web server) can be opened. No additional config entries are required.

This allows the ULC UX to automatically download the necessary project files to the server-side UI manager and no manual distribution of these files is required.

Deployment Scenarios

Following deployment scenarios are recommended for using the ULC UX:

Note: The configurations described below refer to a small server configuration.

Single System Configuration

In a single system configuration the whole project is running on a single machine.

This configuration is recommended for up to 35 ULC UX connections with a medium amount of dynamic panel elements. For high dynamic panel content the number of ULC UX clients must be reduced accordingly to the increased traffic.

Figure 2. Single System Architecture

Redundant System Configuration

This configuration supports redundant WinCC OA servers for higher availability. In a redundant system the HTTP server uses both of the redundant servers as load balancing hosts (when the HTTP server is running on any of the servers). In this case it is required to run the HTTP server CTRL manager with the parameter “-connectToRedundantHosts”.

This configuration is recommended for 35 to 70 ULC UX connections with a medium amount of dynamic panel elements. For high dynamic panel content the number of ULC UX clients must be reduced accordingly to the increased traffic.

Figure 3. Redundant System Architecture

Multi System Configuration

For large sized projects with a high number of ULC UX connections or when using panels with a high number of dynamic elements a configuration with multiple web servers should be used.

This configuration is recommended for 35 ULC UX connections per web server with a medium amount of dynamic panel elements. For high dynamic panel content the number of ULC UX clients must be reduced accordingly to the increased traffic.

Putting the web server in a demilitarized zone (DMZ) increases the overall security of your system. For SSO a Key Distribution Server (KDS) in form of Kerberos has to be configured on a dedicated machine. The KDS has to be reachable from every host which is in involved in the ULC UX configuration (WinCC OA Servers, HTTP Servers, Web Browsers, etc)

Figure 4. Multi System Architecture

Recommendations

Following recommendations should be considered when planning a WinCC OA project and the design and functionality of the panels that should be displayed inside the browser.

  • Having a high number of dynamic elements (animations, color changes, etc.) inside of the panels should be avoided as they cause an increased CPU load on server and a higher traffic load on the network.
  • The WinCC OA project and the WinCC OA web server should be deployed on different computers to avoid influences on the WinCC OA server project (Event, Data, etc) due to higher loads and CPU usage of the ULC UX (e.g. due to a high number of client connections). If the web server and the project cannot be split to different machines a corresponding number of RAM and CPU capacities are required.
  • When using SSO it is recommended to use a redundant Active Directory to provide higher availability of the service.
  • The recommended number of ULC UX connections is based on the assumption Windows is used as web server operating system. When using a Linux distribution as operating system for the web server the recommended connection count increases from 35 to 55 connections per web server.