TechArchive

Original article date: June 2000

Drives are now more sophisticated than ever before, but what is the best way to program them? Tommy Miller reports on a new toolset based on function blocks

For run-of-the-mill drives applications (no pun intended), engineers are now almost spoilt for choice in terms of the number of frequency converters available. Even for more complex tasks, perhaps where many more parameters need to be set, there is a wide range from which to choose. So for some people, one of the most important selection criteria is not the performance, size, cost, or after-sales support, but the programming tools that are offered by the drive supplier.

Although a great deal can be achieved with modern hand-held control panels (and even the popular detachable-front-panel type), engineers are understandably more comfortable working on complex programs at a PC, whether a desktop or laptop machine.

Whilst huge advances have been made in the user-friendliness of PC-based tools for programming PLCs – especially when compared with the traditional ladder logic systems – it is arguable that programmers of variable speed drives have not been as well served. That is, until recently, with the introduction of a function block programming tool from Vacon. Furthermore, the latest version has seen some significant changes to enhance the graphical editor. The FC1131-3 Engineering Toolset is, as the name suggests, based on the IEC 1131-3 standard for PLC programming software, so any engineers familiar with many of the current crop of PLC tools should feel at home with this drive programming software. Vacon has designed the toolset to be used with its CX, CXL and CXS frequency converters, which have current ratings in the range 0.75kW to 1.5MW and voltages from 230V to 690V.

PLC-type functions

Among the PLC-type functions that can be programmed, there are boolean logic functions, timers, counters, comparators and flip-flops. It is also possible to work with analogue signal processing and scaling, ramp control, PI-controllers, filters and integrators. Indeed, the toolset gives the user very easy access to the control logic and parameters of a frequency converter, so is said to be particularly suitable for system engineers or OEMs with requirements that are out-of-the-ordinary.

Users can readily create applications using Vacon’s standard applications as a starting point. This makes it even easier and quicker to develop specialist applications than it would be if starting from scratch. In addition, the software package includes tools for downloading, debugging and commissioning applications. Oh yes, and to make sure that you get up to speed as quickly as possible with this powerful package, Vacon is throwing in two days of free training!

• Vacon

June 2000