Internet tools – home in on data acquisition

Plug-and-play is the name of the game in data acquisition and control. And now, even the `Net is in on the act BY Chris Webb

Access to the Internet gave users the chance last summer to view live data from out of this World. Scientists at NASA were monitoring an experiment on board the Endeavour space shuttle and downloading the data to a Web site for unrestricted access. A gimmick? National Instruments’ Andy Penney thinks not.

`There’s no reason why the `Net shouldn’t be used in a similar way for data sharing in a whole range of industrial applications.’ Already, in the US, the medium is moving in on MMI and SCADA data sharing.

The NASA experiment was using LabVIEW graphical instrumentation software to monitor the status of the BETSCE (pronounced `Betsy’) experiment, a cooling device capable of producing temperatures below 10srK without the vibration typically produced by standard refrigeration techniques. The Web page showed the status of a number of experimental parameters, including temperature and pressure of the coolant and the status of valves.

OK, you say, so what’s the relevance to industrial data acquisition and control (DA&C)?

According to Penney, there are a number of industries that could benefit from the use of the net to share data remotely. Applications in the US include, for example, hazardous nuclear waste sites where the temperature of the material is monitored remotely by thermal imaging and telemetry link and the data posted to a Web site for viewing.

Will we next year be reporting innovative uses of the `Net in industrial applications in the UK? Watch this space.

In the US, so often an early indicator of trends to follow this side of the Atlantic, PCs running the Windows `95 operating environment continue to dominate data acquisition. But NT is catching on fast, and a number of respondents to C&I’s telephone poll reported a marked shift towards NT by the technical community, particularly since the introduction of version four with its improved ruggedness and plug-and-play capability.

Bundled designs

Industry-wide, the integrated approach to DA&C, where hardware and software are offered as a package, is predominant. Ian Bain, operations director at Sunnyside Systems, says a system will typically be supplied with signal conditioning, data conversion, processing and report generation in a single package. Users don’t want the bother and don’t have the resources to develop their own software.

The low cost approach is a move away from rack-based machines, to connect sensors up to a PC and monitor in real time.

Which explains the growing popularity of the PCI as an important bus for desktop machines and plug-in boards whose performance in terms of resolution and speed is on the up and up. Manufacturers are increasingly being encouraged to offer drivers in the quest for genuinely open architecture. Consequently, front end software like Hewlett Packard’s HP Vee will accept a wide range of boards.

Companies like Amplicon offer a comprehensive set of software drivers. Surprisingly, given the hype afforded the application of notebooks in the DA&C market just 18 months ago, marketing director Ian Waterman says they have been slow to follow through with volume sales despite the obvious benefits of portability which they represent.

`They’re seen as too fragile,’ he told C&I, a point which would appear to be borne out by a report from Fieldworks of the US, which states two out of three notebooks sold into industry are trashed in the first 12 months.

Seizing the opportunity, Fieldworks produces a rugged laptop specially designed for harsh environments. Selling at around three times the price of a machine available in the High Street, they are nevertheless catching on. Amplicon has sold numerous to clients such as Orange and the MoD.

Sluggish acceptance of notebooks has had a proportionate impact on sales of PCMCIAs. Nigel Trevarthen, DA&C product manager at Adept Scientific, agrees there is still a perception of PCMCIAs having a limit to the range of signal types they can hook up to. But it is changing.

Hewlett Packard, meanwhile, has designed a high speed DA&C subsystem onto a single VXIbus module which it says can simplify programming for the user and reduce the need for a costly embedded computer running a real time operating system.

The stand-alone operation of the intelligent multi-function VXIbus card permits using high level software such as HP VEE, LabVIEW, or LabWindows to further ease the programming effort for the user. The user can now utilise powerful operator interfaces, along with data display/analysis, and concentrate on the application solution instead of integrating multiple VXIbus cards with an embedded computer.

Several new packages

Software developers regard data acquisition and control as something of a rich vein, commercially, as is evidenced by the formidable array of packages hitting the shelves on a monthly basis. Among the most recent are two 32-bit data acquisition and analysis software packages announced by Fluke. NetDAQ Logger for Windows 95 and NT include view menus, tool and status bars, longer file names and support for both direct connection to a PC or general networks.

At the same time, Fluke is offering an updated version of its Trend Link, with advanced trending and analysis 32-bit configuration. It operates with the company’s full-line of portable and networked data acquisition products, including NetDAQ and Hydra.

DATAshuttle Express, from Strawberry Tree, is the latest offering from Adept Scientific. It incorporates transducer excitation and plugs into the PC’s parallel port. Modular in design, it allows users to connect a large number of channels.

As ease of set-up becomes the industry norm, so does the number of hardware and software products which replace the necessary familiarity with the new technology.

FieldView is a case in point. This automatic set-up, configuration and data logging PC Windows software package from Field Electronics scans an RS485 communications link to interrogate and identify any Series 1000 instruments that are connected, then automatically sets up a matching logging and display configuration on the PC. Drop down dialogue boxes can be used to configure remote units.