Navigating the Sigma Web Framework interface

The Sigma Web Framework comes with several built-in screens, discussed in this section. These screens permit the user to modify logins, modify system parameters, and schedule the execution of background programs on the system.

• Login Screen. This screen allows an administrator to add, edit and delete system logins. The screen is used both by the native Apache HTTP server, but also required if the administrator elects to run Sigma with a third-party HTTP server, such as Microsoft IIS.
• ODBC Screen. This screen assists in interfacing the Sigma system to an external SQL database using the Microsoft "Open Database Connectivity" standard.
• Parms Screen. This screen allows an administrator to modify specific performance parameters of the framework, including colors, timeouts, and operating modes.
• Schedule Screen. This screen allows an administrator to configure the built in scheduler of Sigma, which permits programs to be launched on system startup and shutdown, as well as launched at periodic intervals.

The above screens are a part of all Sigma implementations, regardless of the applications and screens that may also exist. Each screen is detailed in the sections that follow.

Additional notes

• Sigma comes with some predefined screens, which permit users to modify system logins, modify parameters, and schedule tasks. These are a standard part of all Sigma Framework implementations.
• The Login screen permits the user to create username and passwords, and assign access rights to users. The passwords are copied to the Apache HTTP server password file. Passwords are encrypted on the disk.
• If the administrator elects to use IIS or some other web server, the Sigma username still needs to be recorded in the "Login" database to assign proper access to applications. (The password field may be ignored if the administrator is using IIS authentication.)
• The Parameters screen affects all users, and allows system colors, CGI timeout, and other parameters to be viewed and modified by the administrator.
• The "Default Access" parameter can be used to limit access as follows: If a user is not recorded in the Sigma application, that user is assigned a "Default Access" of either "admin", "user", "guest", or "disabled", where the default setting is "disabled".
• The Scheduler program allows the user to schedule periodic tasks, which can be used to perform system maintenance tasks, or can be used to run programs that automatically generate HTML files and screens.
• All of the screens in this section are accessible ONLY to users given "admin" access to the Sigma interpreter.

This section contains the following topics: