Types of NiagaraAX programs

There are typically four different programs (or processes) associated with a NiagaraAX system. These programs and their network communication are illustrated in the Figure 1

This is the NiagaraAX runtime – a Java VM which runs a NiagaraAX component application. Often the term Supervisor or JACE will be used interchangeably with “station.” Technically, the term station describes the component runtime environment common all to all platforms, and Supervisor and JACE describe the hosting platform.

This the NiagaraAX engineering tool – a Java VM which hosts NiagaraAX plugin components.

This is a native daemon process. The daemon is used to boot stations and to manage platform configuration such as IP settings. On Windows platforms, the daemon is run in the background as a Window's service. On QNX it is run as a daemon process on startup. The most common way to access daemon functionality is through Workbench. A connection to the daemon is established via the “Open Platform” command which opens a PlatformSession to the remote machine. Workbench provides a means for accomplishing platform tasks, such as the following:

installing and backing up station databases

launching and monitoring stations

configuration of TCP/IP settings (QNX, Windows XP, Server 2003)

installation and upgrades of the operating system (QNX only)

installation and upgrades of the Java virtual machine (JVM)

installation and upgrades of the NiagaraAX software

installation of lexicons for localization

installation of licenses

This is a standard web browser such as IE or FireFox that hosts one of NiagaraAX's web user interfaces. NiagaraAX provides both server side and client side technologies to build web UIs:

On the server side, the WebService component provides HTTP and HTTPS support in a station runtime. The NiagaraAX WebService provides a standard servlet engine.

There are two client side technologies provided by NiagaraAX to support the browser user interface (BUI). The first is Web Workbench, which allows the standard Workbench software to be run inside a web browser using the Java Plugin. Web Workbench uses a small applet (wbapplet) to download modules as needed to the client machine and to host Workbench shell. These modules are cached locally on the browser's hard drive.

In addition to Web Workbench, a suite of technology called Hx is available. The Hx framework is a set of server side servlets and a client side JavaScript library. Hx allows a real-time user interface to be built without use of the Java Plugin. It requires only web standards: HTML (Hypertext Markup Language), CSS (Cascading Stylesheets), and JavaScript.