One- and two-axis drives feature Canopen interface

Paul Boughton
CNC vendor NUM is adding a family of single- and dual-axis Canopen drives to its range. These units are said to be economical for positioning requirements on machine tools, thereby extending NUM's high-performance CNC control range in a way that helps customers to build machinery with highly optimised and cost-effective hardware.

The new intelligent Canopen drives are available in seven single-axis versions with output ratings from 8.9-100A(rms) continuous (10-141A peak), and three dual-axis versions with output ratings from 6.3 + 6.3 to 20 + 20A(rms) continuous (10-35A peak). These options provide machine tool builders with a 'granular' choice to ensure that the control system hardware's capabilities match the machine specification.

As an extension of NUM's long-established NUMDrive C range, these drives are claimed to offer one of the highest power densities on the CNC market, together with a simple assembly concept for building large multi-axis systems. Both of NUM's CNC controller kernels, Flexium and Axium Power, are available with Canopen interfaces and are compatible with the new drives.

The CANopen drives implement a subset of the standard DSP 402 drive profile and are useful for performing auxiliary tasks to the co-ordinated multi-axis control of the machine's tooling, such as feeding and unloading material.

Built-in intelligence means that the drives are simple to program and use, and can perform sophisticated movement profiles following a single command. Development is further simplified by NUM's development software, which automatically recognises the drives and provides all the required libraries and functions blocks.

Mechanical compatibility provides another advantage, avoiding the need to create custom mounting arrangements for third-party hardware and the additional assembly time associated with such 'hybrid' systems.

Bill of material costs can be reduced because the drives are designed to operate from a common DC bus. Almost any realistic combination of NUM's new Canopen drives and its servo/spindle motor drives may be powered by just one of the company's book-style power supply units. This can eliminate numerous components such as connectors, cabling and filters from the bill of materials, compared with alternatives on the market that can require a second power supply. Significant energy savings can also be made via power regeneration back into the shared DC bus during the deceleration phase of an axis.

Jan Koch of NUM states: "When machine builders select an off-the-shelf CNC controller they inevitably have to accept that supplier's system partitioning decisions related to the numbers and types of axes provided on each platform, and its cost implications. These new single- and dual-axis positioning drives allow NUM clients to choose exactly the right quantity and type of axes, and all using a common mechanical system.

"Similarly, the development toolset makes it simple to develop control programs using the controller's IEC 61131-3 compliant PLC. Problems related to programming and integration of components are often not fully allowed for when selecting products such as this, resulting in extra costs, time to market delays, and often problems when commissioning new CNC machinery."


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