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Fig.1: LabVIEW 5.0 features a new Instrument Wizard that simplifies the configuration of GPIB, VXI and RS-232 instruments. The Instrument Wizard automatically identifies and tests the instruments connected to the system, installs the required driv­ers and then generates application examples using these drivers. New version has more features and is easy to use Labview 5.0 Virtual Instrumentation Software LabVIEW has been around for 11 years and has become known as the leading software package for instrumenta­tion and control. Any engineer or technician familiar with Wind­ows 95 should take to it like a duck to water. It is now over a decade since Lab­ VIEW was first released. This graph­ ical programming software from Na­ tional Instruments was introduced as a development tool to design, develop and modify instrumentation systems. The goal of LabVIEW has always been to simplify programming tasks so that scientists and engineers could fully utilise the capability of PCs and at the same time get their jobs done quickly and easily. Since its first release, LabVIEW has grown to become the industry-lead­ ing development software for data acquisition, test and measurement and analysis applications. National Instruments refers to LabVIEW as a programming environment, in much the same way as Windows 95 is an environment. So much so, that quite a few third parties have developed LabVIEW applications and these have been updated with the release of Version 5. So there is effec­tively a whole suite of new software and applications. As PCs continue to find use in more and more demanding applications, software developers are constantly looking for ways to get more out of them. Many software developers are also taking advantage of software de­ velopments that include ActiveX and Java to enhance their applications. Some of the features of the new version of LabVIEW are as follows: Instrument Wizards Used in some other Windows 95 programs such as Microsoft Word, Wizards are incorporated into Lab­ VIEW 5. These simplify the con­ figuration of GPIB, VXI, serial and computer-based instru­ m ents. The Instrument Wizard automatically identifies and tests the instruments connected to the system, installs the required drivers and then generates application examples using these drivers – see Fig.1. March 1998  9 Fig.2: LabVIEW 5.0 features a new ActiveX automation server that gives the users the ability to remotely call LabVIEW programs from other programming languages such as Visual Basic, Visual C/C++, Lab Windows/CVI, standard C languages, Microsoft Excel or even another copy of LabVIEW. Not only does the Data Acquisition (DAQ) wizard automati­cally generate a solution for the user, it also creates the LabVIEW block diagram so that users can modify the application as their needs change. These DAQ Wizards have also been added to the Macintosh platform. ActiveX Containers This feature of LabVIEW allows peo­ ple to share code across programming environments. Reusable components or objects of code that are written in one language but can be called from a variety of other environments are important simply because they allow code to be reused that would otherwise need to be completely rewritten. The most common type of reusable component is an ActiveX control and these can be embedded into any ActiveX container – see Fig.2. Today, the most popular ActiveX containers are Visual Basic and Visual C++. With the introduction of Version 5.0, Lab­ VIEW is now an ActiveX Container. 10  Silicon Chip This means that users can easily drop any ActiveX control or document onto a LabVIEW front panel, edit it by clicking on it and control it using a graphical approach on the block diagram. Thus, a user might embed a National Instruments Com­ponent­­ Works control, a web browser control, a HiQ Notebook, an Excel spreadsheet, a Word document, a calendar control or any of more than a thousand other controls and documents available over the Internet and in software worldwide. This means that users are no longer limited to the built-in controls available in Lab­VIEW but can take advantage of controls written in other languages. Equally important, they do not need to do any complicated programming to take full advantage of these other controls. Automation Servers These allow integration of LabVIEW programs into other applications. For example, Visual Basic is often used as a tool for developing front-end appli­ cations for databases. LabVIEW, on the other hand, is an industry-leading software tool used to develop data acquisition and production test sys­ tems. If a user could integrate the two applications together, or call LabVIEW programs from Visual Basic, then they would have the flexibility to use both tools in an application that stores production test data in a database. LabVIEW 5.0 features an Auto­ mation Server that gives users the ability to “remotely” call LabVIEW programs from outside the LabVIEW environment. Thus, the user can call a Lab­ VIEW Virtual Instrument (VI) from any ActiveX Automation client, such as a program written in C, Visual Basic, a Microsoft Excel macro or even from another copy of LabVIEW. Thus, much in the same way that a user calls a DLL from a program, now they can call a LabVIEW program from another appli­cation. In addition, the user can control the entire LabVIEW development environment itself from another program. Distributed Computing Tools These are used to easily create dis­ Fig.3: another feature of LabVIEW 5.0 is Translation Tools for multilingual user interfaces and software translation. This enables the same LabVIEW program to be run in numerous languages. tributed LabVIEW appli­cations that will execute on computers across a heterogeneous network. Certain applications require that their execution take place on multi­ ple machines. If users must quickly execute ex­tremely intensive routines, they may want the ability to divide the tasks onto different computers. Or if remote acquisition requires the user to collect data from various locations, a distributed system may also be the best approach. Typically, distributed systems are complex to write because they require a great amount of overhead code to pass data between the computers or to execute calls on remote machines. With LabVIEW 5.0, users can create distributed systems with ease. Suppose a user has a collection of acquisition routines and wants to call each of them at any time from any of several loca­tions. Many programming environments require networking functions to send commands and data to other computers; those remote com­puters must constantly listen for a connection. To send and receive data, the user must perform tedious data conversions to send information across the network. With LabVIEW 5.0, users simply create their initial pro­ grams, load them on all machines where they might execute and then write a simple program to call them at a specified location. When users execute the “controller” program, it simply reads the specified target and executes the function at that location. When using the ActiveX interface the server automatically launches LabVIEW if it is not already open, so LabVIEW does not need to run constantly on the target computer. The user can choose to display the program on the target machine as it runs or have the program execute in the background. worldwide are well documented and easy to use. In addition, as interna­ tional markets continue to grow, it becomes ever more important that both documentation and software be translated into the end-user’s native language – see Fig.3. With the new documentation tools in LabVIEW 5.0, users can automat­ ically generate software documenta­ tion in the form of HTML (hypertext mark-up language) and RTF (rich text format) formats. Thus, with the click of a mouse, an entire user manual, function reference manual or online help system can be generated. No other tool makes the tedious task of this documentation so simple. Translation tools These help large application de­ velopment by providing the ability to compare graphical code to determine the differences between them – see Fig.4. These are used to create multilin­ gual user interfaces and facilitate the translation of software. Software developers face several challenges to make their software successful worldwide. Good docu­ mentation is often a time-consuming task which some people choose to ignore. However, studies indicate that the most successful software packages Graphical differencing tools Multi-threading To address the requirement of high-performance, very reli­able ap­ plications on PC platforms, modern operating systems, such as Windows March 1998  11 Fig.4: the Graphical Differencing Tool in LabVIEW 5 enables the differences between two programs to be highlighted. This enables new versions of instrumentation programs to be generated quickly. Fig.5: the LabVIEW-based Intellichart from Densitron (Kent, England) is a paperless chart recorder with a TFT colour display, touch screen controls and LAN interface in a robust case. It was designed for clean room environments as encountered in activities such as microchip production or food processing. The graphical tools in LabVIEW 5 mean that users can easily set parameters such as trigger level, scan speed, paper speed, X scale and so on. For further information, contact National Instruments or the web site at www.densitron.com 12  Silicon Chip SILICON CHIP SOFTWARE Now available: the complete index to all SILICON CHIP articles since the first issue in November 1987. The Floppy Index comes with a handy file viewer that lets you look at the index line by line or page by page for quick browsing, or you can use the search function. All commands are listed on the screen, so you’ll always know what to do next. Notes & Errata also now available: this file lets you quickly check out the Notes & Errata (if any) for all articles published in SILICON CHIP. Not an index but a complete copy of all Notes & Errata text (diagrams not included). The file viewer is included in the price, so that you can quickly locate the item of interest. The Floppy Index and Notes & Errata files are supplied in ASCII format on a 3.5-inch or 5.25-inch floppy disc to suit PC-compatible computers. Note: the File Viewer requires MSDOS 3.3 or above. OR D ER FOR M PRICE ❏ Floppy Index (incl. file viewer): $A7 ❏ Notes & Errata (incl. file viewer): $A7 ❏ Alphanumeric LCD Demo Board Software (May 1993): $A7 ❏ Stepper Motor Controller Software (January 1994): $A7 ❏ Gamesbvm.bas /obj /exe (Nicad Battery Monitor, June 1994): $A7 ❏ Diskinfo.exe (Identifies IDE Hard Disc Parameters, August 1995): $A7 ❏ Computer Controlled Power Supply Software (Jan/Feb. 1997): $A7 ❏ Spacewri.exe & Spacewri.bas (for Spacewriter, May 1997): $A7 ❏ I/O Card (July 1997) + Stepper Motor Software (1997 series): $A7 POSTAGE & PACKING: Aust. & NZ add $A3 per order; elsewhere $A5 Disc size required:    ❏  3.5-inch disc   ❏ 5.25-inch disc TOTAL $A Enclosed is my cheque/money order for $­A__________ or please debit my ❏ Bankcard   ❏  Visa Card   ❏ MasterCard Card No. Signature­­­­­­­­­­­­_______________________________  Card expiry date______/______ Name ___________________________________________________________ PLEASE PRINT Street ___________________________________________________________ Suburb/town ________________________________ Postcode______________ Send your order to: SILICON CHIP, PO Box 139, Collaroy, NSW 2097; or fax your order to (02) 9979 6503; or ring (02) 9979 5644 and quote your credit card number (Bankcard, Visa Card or MasterCard). ✂ NT and Windows 95, as well as Sun Solaris, are “multi-threaded”. Applications that take advantage of multi-threading have a number of benefits, including better CPU utili­ sation, better system reliability and user interface response and the ability to take advantage of multiprocessor machines. However, only a few applications today are multi-threaded, simply because it is difficult to implement. LabVIEW Version 5.0 solves this problem because, as a dataflow pro­ gramming language, it is inherently parallel in nature. This makes it nat­ ural for users to create code that can execute simultaneously in separate threads. Thus, it is the ideal language in which to develop multi-threaded applications. LabVIEW multi-threading technol­ ogy is built into every virtual instru­ ment (VI), or LabVIEW program, so it is not neces­sary for the user to learn any new programming techniques. In fact, the user does not even need to know what multi-threading is to ben­ efit from it. However, for expert users who want to have specific control over threads, such as changing thread priori­ties, the flexibility is available in a straightforward dialog box option. All of the complex tasks of thread management are transpar­ently built into the LabVIEW execution system, such that users need never concern themselves with the tedious details of thread management. Thus, while tex­ tual-based programmers must learn new and confusing programming practices to create a multi-threaded application, a LabVIEW user simply writes a VI (virtual instru­ment) as he or she always has. And to make an existing LabVIEW VI multi-thread­ ed, users simply have to load their LabVIEW programs into Version 5.0. For a more complete explanation of multi-threading and its benefits, there is an Application Note titled “Creat­ ing Multi-threaded Applications to Maximise System Performance and Reli­ability.” For further information on Lab­ VIEW 5.0 or the full range of instru­ mentation products, contact National Instruments Australia, PO Box 466, Ring­ w ood, Vic 3134. Phone (03) 9879; fax (03) 9879 6277. Readers can also access information by email at: info.australia<at>natinst.com or at http://www.natinst.com SC March 1998  13