Group3 Technology Ltd.

Specialists in Magnetic Field Measurement & Distributed Control Systems

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Group3 Software

Control software is required to permit control and monitoring to be performed by the computer, and for the status to be displayed on the computer.

PC based control packages.

One huge advantage of using a PC as the control computer is that it allows use of any of a number of commercially available control software packages. These packages have had hundreds of man years of programming experience put into them - a level of input no single physics institution could hope to give to a project. The packages are also fully documented, come with on line help, and offer support and upgrades.

Using one of these commercial packages a complete novice can get a simple system under control in a week or two. It is useful to have someone in the organisation who has some previous knowledge of such packages, but by no means essential.

Most of the packages support networks of computers, so several computers can share control data.

For any software package to communicate with a Group3 loop controller, a driver must be installed on the computer. Drivers for all Microsoft operating systems are provided by Group3 on an installation CD with each loop controller.

The pricing of the commercial packages sometimes depends on the number of channels that are being monitored and controlled, but a small system can be upgraded to a bigger system at a later date.

Packages currently supported by Group3 are:

• InTouch, by WonderWare Corp
• LabVIEW, by National Instruments

Other packages that have been used to run Group3 hardware are:

• Control3, and other custom software by Pyramid Technical Consultants
• ControlView, by Allen Bradley.
• VISTA, by Vista Control Systems inc.
• EPICS
• a number of custom written interface software drivers, particularly for the VME and CAMAC loop controllers

Software Packages

1. InTouch

   Very graphical - the user can draw any screen pictures, and animate the objects according to monitored values - objects can move, meter needles point to the correct value, tanks fill, warnings flash etc.

   This package has the best graphics, on line help, and is the easiest for a complete beginner to start up with. It has all the value displays, historical data logging, alarms and graphing one could want. Its automatic control language is a bit limited - action scripts are easy to write, but have to be written in a script language similar to BASIC. A further module is available, at a price, to allow control functions to be written in 'C'.

   It is a windows based program, and communicates through the DDE protocol, which can slow down the graphics update if many values all change at once. Pricing depends on the number of channels, with changes at 64, and 256 points. Requires an additional program from Group3, a DDE driver called G3DDE32.EXE.

2. LabVIEW

   A very popular scientific analysis and control package. A limited range of graphical elements to choose from. Has a very good range of data analysis tools. It has a very fast update rate. Becomes easy and very powerful once the basics have been learned, but is perhaps cryptic to a novice. It is really like computer programming using graphics rather than lines of code. As such the language and concepts used would be easier for a computer programmer to learn. Not recommended for a novice unless someone else in the institution has some previous knowledge of it.

   Pricing not dependent on the number of channels in the system, and considerably less expensive than alternatives for big systems.

   Group3 has written a program block for LabVIEW which provides a collection of virtual instruments (VIs in the LabVIEW jargon). These VIs handle all the set-up tasks, and access to all I/O data in a Loop Controller. This frees the LabVIEW programmer to concentrate on control aspects without having to learn the details of the interface.
   

3. C++ toolkit

   Group3 has developed a comprehensive C++ toolkit to greatly speed up the writing of code to drive a Group3 Control system. It contains sample code and routines to handle all the set-up tasks, and to access all I/O data in a Loop Controller. It handles all the dual port arbitration and error handling. Highly recommended for people doing their own software - even if not using C++, the documentation and examples will save considerable time.

The above comments are only a few brief statements on what are very complex software programs. Certain programs have features that others lack. If you are uncertain which package is most suitable for your application please ask your local Group3 representative for further comments.

Alternatively, the user may write their own control software to drive the Group3 system and operate the controlled plant. Sufficient information is given in the Loop Controller Programmers Manual to allow a software engineer to write code that will configure the LC and set up communication on the fiber optic loop.

This is the usual approach for people using the VME and CAMAC loop controllers.

Software Revisions

Group3 Control - EPROM History and Compatibility

Any software upgrade is checked for compatibility with previous versions, but to ensure best performance and access to the new features an upgrade offers we strongly recommend that all EPROMs on the loop are upgraded to the same version number.

NOTE: To access new features requires version 4.0 in LC and DI, and FOTo access new features requires version 4.0 in LC and DI, and FO

NOTE: Support for ninth bit protocol on loop removed - SDLC now standard.

NOTE: Faster Watchdog kick - required for new (16000027C) processor board.

NOTE: To access new features requires version 3.3 in LC and DI.

NOTE: Totally revised software - will not run SDLC in DI with non S2 micro

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