Ethernet networks and the Web have revolutionised how we disseminate information and distribute tasks throughout a company. The integration of systems and processes begins with sharing information and data. For example, by sharing production test data between the manufacturing and design teams, engineers can identify and correct designs that have a high rate of production test failure.
The Web The Web has changed the way businesses communicate by providing companies with a new way to deliver data, connect processes and systems, and conduct business-to-business transactions using their existing network infrastructure The Web often refers to a broad spectrum of technologies that facilitate the exchange of information between systems, departments, and customers. These technologies include TCP/IP, Web browsers, and HTML. So why not harness this infrastructure to logon and remotely view and control measurement systems? The Technical Enterprise As measurement systems find their way onto the company network, they become part of the technical enterprise. The technical enterprise makes the development of scientific and engineering applications more productive by sharing reports, live data, and distributing applications throughout the laboratory or production environment. Today, most measurement applications include a standalone computer connected to measurement devices through locally connected busses such as PCI, GPIB, USB, or RS-232/485. Distributed and Remote Execution The real power of the network comes from being able to effectively use all the resources available. The network in the technical enterprise is a combination of computers and measurement systems and devices. Using distributed execution, you can remotely use another computer to control the execution of your application. This is often referred to as remote execution and is only slightly different than distributed execution. While splitting an application into too many pieces will result in diminished returns, there are many instances in which distributed execution yields increased productivity.
An example is a measurement system that acquires data in hazardous or remote environments, because it may be too expensive or time consuming for engineers to continually change a measurement system. This is often true in environmental testing. It can require hours for an environmental chamber to achieve the desired settings. This may cause some frustration for system designers who must constantly tweak the system. Using remote execution, a system designer can reconfigure and change the system for many different tests without ever entering the chamber. This concept easily extends into hazardous and remote environments. There is, of course, a lag time when operating remote data acquisition over the web. As long as the data concerned has greater than a millisecond sensitivity and you are satisfied with delays of up to a second then there should not be a problem.
Many technologies for distributing and controlling remote execution exist. At a low level, remote procedure calls in C and C++ and remote method invocation in Java allow users to programme and execute functions remotely. Many applications in measurement and automation expose distributed and remote execution through ActiveX, including National Instruments’ LabVIEW. LabVIEW further extends this capability by allowing users to distribute execution without ActiveX and across the many platforms, including Microsoft Windows, Apple MacOS, and Linux.
For example at University College London. Steve Boon, senior experimental officer, is using LabVIEW to control experiments on ice core samples. Due to the intense pressures and stresses the samples are subjected to, the PC controlling the servo system is located in the experimental chamber and data captured from this PC is passed to another PC, located in the control room, which processes, presents and stores the data. This distributed system ensures that experiments can be run without endangering operator safety.
Online and Web Reports The simplest way to share information is by publishing a summary or report. The HTML-based web page is becoming the most common method to report information and easily offers many advantages over printed reports. Many instruments available today allow you to configure them or view results through a Web page. These instruments are designed with Ethernet ports and Web servers and can be added to ‘the technical enterprise’. Displaying the raw data an instrument provides may be useful to the system designer, but the power of Web reporting is apparent when the raw data acquired by an instrument is transformed into useful information through analysis, graphs, and trend comparisons before being published.It is very easy to integrate Web report generation into instrumentation and analysis software. Products like National Instruments’ LabVIEW and Mathworks’ MATLAB can quickly publish reports to the Web. Microsoft Excel is one of the most popular tools for generating reports and can easily create Web reports, permitting anyone to view the status of a measurement system without having to remember where to find the latest printed report. The information in an electronic report should be kept up-to-date, and users should always know where to find it by bookmarking the URL (universal resource locator) in Web browsers.
Streaming Data A report offers a static view of compiled information. While this information may be easy-to-read and may give a summary of a completed test, it does not provide an easy way to access the data that created that report. In many applications, real-time access to acquired data is needed to control or monitor a process or test across the network. The results of one measurement or automation process can be passed directly into the next process. Or any monitoring task that requires live streaming of data between applications can be developed.
Many commercial technologies allow you to stream information between applications including Real Networks real audio format and National Instruments DataSocket for measurement and automation applications