Multitalented inverter gains PLC functionality

Edited by the Engineeringtalk editorial team Nov 1, 2004

WEG's Vectrue CFW-09 inverter now offers users the cost saving benefits of PLC functionality - as well as selectable V/F, sensorless vector, closed loop vector and fieldbus operation.

WEG's Vectrue CFW-09 inverter now offers users the cost saving benefits of PLC functionality - as well as selectable V/F, sensorless vector, closed loop vector and fieldbus operation, all in a single product.

PLC functionality equips the CFW-09 for general digital control tasks, and for advanced positioning and synchronisation applications in areas such as pump control, winding, printing and packaging.

By removing the requirement for a separate PLC, it provides OEMs and users with substantial reductions in equipment, enclosure and installation costs.

Simply by slotting-in a PLC-01 options card to the CFW-09, the drive user is able to perform general I/O control tasks or to employ such functions as positioning with trapezoidal and S profiles (absolute and relative), master/slave/synchronization between two or more motors, or electronic gearbox.

The options card offers the user 100 parameters via software or HMI, the flexibility of programming in a Windows environment using WEG's WLP ladder programming software, and the facility of an RS232 interface with standard Modbus RTU.

Also adding to what is a complete control package, are a homing or absolute feedback feature - which provides the ability to know the exact position of a motor at any given time, a real time clock, encoder power supply and isolated encoder input, nine digital inputs and three relay outputs rated at 3A.

The operation of the PLC-01 options card is optimised by the powerful 32bit RISC microprocessor at the heart of the CFW-09 drives.

The level of control provided by this unit ensures the fastest dynamic response and absolute control of speed and torque in the most demanding of applications.

Performing a pivotal role in many of these applications is the CFW-09'S novel "optimal braking" feature, which is employed for tasks that require reduced braking times or the stopping of high inertia loads.

Traditionally, conventional variable speed drives (VSDs) have relied on dynamic braking resistors to dissipate excessive heat regenerated in their DC links under braking.

In contrast, "optimal braking" provides sufficient braking performance to eliminate the need for the resistor in the majority of applications.

This results not only in cost savings but also enables highly dynamic performance drive systems with braking torques of about five times that of typical DC braking systems.

The CFW-09 series of variable frequency drives is designed to deliver high performance and reliable operation across the wide power range from 1.5 to 1000kW.

The range is suited to standalone drive applications or can be employed as an intelligent "nodes" in high-speed factory control networks.

To assist easy network integration, the drives are supported by a range of optional, plug-in Profibus DP, DeviceNet and Modbus RTU fieldbus modules.