1.3.2.2         Web Server

WebAccess uses an ordinary web server as our Project Node.

Microsoft IIS (Internet Information Server) is a standard option in Windows 2000  Professional and Server version, Server 2003, XP Professsional, Server 2008, Vista Business and Vista Ultimate. You can install IIS from your Windows 2000 Professional, Windows 2000 Server or Windows XP Professional Installation CD.

The Project Node provides the initial link between Clients and the SCADA nodes.  After that link, the Web browser clients communicate directly to the SCADA Node.  The connection to the Project Node is dropped until the Refresh button is pressed (which not normally done while using WebAccess).  The 10 simultaneous connections provided by Windows 2000 and XP Professional will support much more than 10 users.  Server 2008, Vista Business and Vista Ultimate allow unlimited connections.

The Project Node is a Web Server. At least one web server is required in order to do database configuration, graphics building and to download run-time databases from the Project Node to the SCADA Node(s).  A Project Node web server is also needed to access the centralized logs.

SCADA nodes are usually not web servers. For stand alone installations the Project Node and SCADA node are often combined on one PC.  A SCADA node can optionally be a web server as a way to provide redundant paths for remote Clients to connect to the SCADA Node(s). For more information, see 16.1.3.2 Connect without Project Node.

A redundant Web Server is easily implemented to point users to the SCADA Nodes. (SCADA Nodes can be redundant also).

This makes WebAccess a "fully" web-based solution.  WebAccess enables engineers, integrators and vendors with the ability to support their systems remotely over an intranet or the Internet using an ordinary web browser.

It is possible for remote Clients to connect to SCADA nodes without a web server.  See 16.1.3.1 Connect without Web Server, for more information.

ASP (Active Server Pages) are used as the Engineering Tool in WebAccess, for HTML reports, and initial client connections. An ASP enabled Web Server is required. Microsoft IIS is the only ASP enabled Web Server software suite supported by WebAccess SCADA and HMI software.

For more information, see the Project Node System Requirements and IIS on the Project Node.  See the Troubleshooting section to Determine if IIS is installed on your Project Node computer.

Using WebAccess with Windows Vista

For WebAccess Project Node software to run on Windows Vista, install IIS on your project nodes first with following IIS features turned on before installing WebAccess Node.

Enable IIS (Internet Information Service) before installing Project Node software!

IIS is the “web server” in Windows. IIS must be enabled before installing the Project Node software to allow WebAccess files to be installed properly.

IIS is disabled by default in Windows Vista.  For those of you who wish to use WebAccess Project Node on Windows Vista, please enable IIS on your project nodes first with following IIS features turned on before installing WebAccess Project Node software.

To enable IIS in Windows Vista Business:

1. Start -> Control Panel -> Programs -> Programs and Features

2. On the left Side Bar select “Turn Windows features on or off”

3. Wait for the Windows Features dialog box to open and fill, then expand “Internet Information Services”.

In case the above  JPEG images does not appear in this, the typical settings for IIS in Vista for use with WebAccess on the Project Node as tested are:

Internet Information Services – ON

FTP Publishing Service – OFF (optionally ON, not needed and is security risk)

Web Management Tools – ON

IIS 6 Management Compatibility - ON

                             IIS 6 Management Console – OFF

                             IIS 6 Scripting Tools – OFF

                             IIS 6 WMI Compatibility – OFF

                             IIS Meta base and IIS 6 configuration compatibility – ON

                   IIS Management Console – ON

                   IIS Management Scripts and Tools – OFF

                   IIS Management Service - OFF

 

World Wide Web Services - ON

Application Development Features – ON

                             .NET Extensibility – OFF

                             ASP – ON

                             ASP.NET – OFF

                             CGI – OFF

                             IASPI Extensions – ON

                             IASPI Filters – OFF

                             Server Side Includes - ON

 

Common Http Features – ON

                             Default Document – ON

                             Directory Browsing – ON

                             Http Errors – ON

                             Http Redirection - ON

                             Static Content - ON

 

Health and Diagnostics – ON

                             Custom Logging – OFF

                             HTTP Logging – ON

                             Logging Tools – OFF

                             ODBC Logging – OFF

                             Request Monitoring – ON

                             Tracing - OFF

 

Performance Features – ON

                             Http Compression Dynamic – ON

                             Static Content Compression - On

 

Security - ON

Basic Authentication - OFF

Client Certificate Mapping Authentication - OFF

Digest Authentication - OFF

IIS Client Certificate Mapping Authentication - OFF

IP Security - OFF

Request Filtering - ON

URL Authorization - OFF

Windows Authentication (optional ON, usually OFF)