Middleware enables Internet-based data acquisition and control
Sep 26, 2000 — by LinuxDevices Staff — from the LinuxDevices Archive — 1 viewsESC, San Jose, CA — (press release excerpt) — Diamond Systems Corporation today announced its new DALI Embedded Remote Access software for data collection, monitoring, and control of remote instruments or systems over the Internet. DALI software utilizes the latest in advanced Internet technologies to provide a complete solution for Web-based access to equipment installed at distant locations.
Due to the extensive use of open standard technologies such as Apache, XML, and PHP, as well as several advanced techniques and concepts incorporated into the design, DALI software provides unprecedented flexibility for users who wish to communicate with and control their equipment and systems via the Web.
DALI Embedded Remote Access software includes: the core Web server that serves the pages and handles security and user authentication; a second Web server that manages data communications and hardware I/O; administrator pages for system configuration; and an Intelligent Email Manager, which generates notification emails (alarms) based on user conditions. All applications run on a single CPU board. An applet builder application is provided for customization of the screen controls, and an automatic installation script installs and configures the product in just a few minutes. Everything needed for a complete remote control solution is provided. The developer just needs to create and upload custom Web pages to provide a custom look and feel.
The server utilizes open standards at each critical point to enable utilization on a wide variety of hardware configurations. For example, DALI software will work on any CPU running the Linux or Windows NT operating system. The back-end I/O hardware interface is generalized to allow other I/O board manufacturers to write drivers enabling DALI software to work with their products. In addition, Diamond is publishing its XML-based DALI communications protocol as an open standard to enable developers to write their own control applications for configurations where an operator display is unnecessary.
How DALI Software Works
DALI includes a library of Java applets that simulate real-life control panel objects to provide monitoring and control of I/O points on the embedded hardware. The style and behavior of these applets can be customized, and they then can be embedded into any standard HTML Web page just like an ordinary image, enabling Web designers to create custom control panels. These Web pages with embedded applets are installed, along with the DALI server, onto the host CPU embedded inside the product. When a user browses the product, he is served these Web pages and can manipulate the applets on the screen to control the product in real time. The applets communicate with the server using the DALI Protocol and can log remote data directly to a local storage device in real-time.
The DALI Web Server Software currently runs on the Linux and Windows NT operating systems. For Linux applications, Diamond utilizes TimeSys Corporation's Linux/RT real-time kernel and can achieve operation at rates of up to 2,000 transactions per second.
For simple, direct control of I/O points, DALI's Java applets can be used out of the box. For more complex actions, DALI contains a unique C-like scripting language with a drag-and-drop user interface for defining the behavior of the control elements. A developer can insert formulas to convert raw sensor data into engineering units or even write entire programs to describe the behavior of a group of applets on a single page acting together. For example, a Web page might contain two applets: one applet, acting as a heater control switch, can be programmed to turn on automatically when the second applet, serving as a temperature reading, falls below a user-defined value. Using this technique, a Web page can automatically control the remote system without user intervention.
Price & Availability
Diamond Systems' DALI Developer Toolkit is being demonstrated at the Embedded Systems Conference. It is being offered to key partners now for closed beta and will be available in full release in Q1 2001. The Developer Toolkit is available directly from the company or through its network of US and international sales offices. Pricing is set at $2,500 for binary distribution and $10,000 for full source code. Run-time licenses are priced based on volume.
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