Function-optimised servo drive reduces costs for OEMs

These new drives deliver a very high level of performance with a peak current capability that is up to twice that of many similar drives on the market - allowing faster acceleration - and offer applications versatility thanks to universal encoder interfacing. However, they also reduce costs by a significant margin compared with other similar drives from Metronix by stripping out the Safe Torque Off feature.

This provides system builders with a very cost-effective drive for applications that do not require advanced functional safety, and where a simpler disabling mechanism based on electrical contactors is all that is required. In numerous other applications, safety disabling features might not be needed at all because the drive is inside a closed system that cannot be accessed during operation. The approach might also be used when machine manufacturers are asked to fit machines with a user's preferred brand of PLC. Due to the complexity and costly commissioning required for some fieldbus-based safety concepts, external safety devices might be preferred. There are a number of machine building companies that have not adopted drive-integrated safety and continue to use external safety devices for various reasons. Or, a machine vendor might choose to offer a proprietary safety concept.

ARS 21xx/23xx SE compact panel/cabinet-mounting drives are available in a choice of six single- or three-phase continuous output power ratings from 0.5 to 6kVA (with peak output powers from 1 to 12kVA). The new drives incorporate two advanced features that are proving very popular with current Metronix customers. The first is a very compact design with integrated line and motor filters plus an integrated brake chopper and braking resistor. This is a typical characteristic of all Metronix drives - which are provided ready to use - avoiding the additional costs of external EMC filters and wiring.

The second feature is an increased overcurrent capability of four times the continuous output rating. This compares with the approximately two times overcurrent rating offered by many other servo drive manufacturers. The feature typically allows the speed of moves and the overall throughput of machines to be increased by factors from around 17 to 25 per cent. Metronix's tests demonstrate that these drives provide overall increases in automation productivity of around 5 to 7 per cent in typical continuous processing applications.

Easy commissioning of drives

Metronix's new drives also feature a universal encoder interfacing capability that allows connection to resolvers, analogue/digital incremental encoders, and single/multi-turn absolute encoders such as HIPERFACE or EnDat. Standard communications interfaces include the CAN fieldbus, compatible with the DS 402 CANopen device profile. One further feature is an SD Card interface, which can be used to store firmware and operating parameters. This allows the drives to be commissioned very easily, and facilitates an easy change-out by maintenance workers without any need for a sophisticated software parameterisation tool. The drives come in case sizes with widths of 54 or 69mm (2.1 or 2.7 inches).

The drives' built-in intelligence provides flexibility for system builders. It allows engineers to create highly cost-effective drive-based systems easily for many common applications requiring one or a few axes, or economic options for subsystems in processing equipment performing functions such as labelling or handling. Other common applications include functions such as synchronising, sorting and a flying saw, and axes that automate auxiliary machinery functions such as set up and guarding. The drives can also be used in more complex multi-axis machinery and plant automation, which can now be designed in a more flexible way thanks to Metronix's expanded drive portfolio.

A powerful and easy-to-use Windows-based software tool for parameterising and analysing the new drives is available. For more complex applications, Metronix offers a motion controller which can be integrated easily.

For more information about the ARS 21xx/23xx SE intelligent servomotor drives from Metronix, please visit www.metronix.de.