A switch to motion control components compatible with the real-time Ethernet Powerlink protocol is simplifying electrical system building for Harland Machine Systems, a manufacturer of ultra-high-speed linear labeling machines. It has substantially reduced the hardware and wiring on a new variant of Harland's Mercury labeling system -- a system designed to apply front and back pressure-sensitive labels, with a throughput of up to 275 products per minute.

Harland's linear machines are built from two main elements: the core machine itself which has six servomotor axes for feeding, positioning, and stabilizing products on a conveyor; plus a modular labeling head with a pair of stepper motor axes -- for applying labels to both front and back of a bottle. Four labeling heads are typically fitted, with auto-change facility for continuous throughput, which allows reel changeovers to take place without stopping the line.

The high speed of the Mercury machine, combined with its programmability for different product types, places stringent real-time demands on the motion control hardware. First, both the main controller and the labeling heads each require several high-speed inputs for product registration. The main controller must also dynamically change the cam motion profiles required for the centering and label 'wipe-down beams,' which center, stabilize, and complete label wipe-down on the product. This enables a quick changeover between product types.

The previous Mercury machine needed seven discrete motion controllers for a typical dual-head configuration. An Ethernet Powerlink controller from Baldor, Fort Smith, Ark., reduces this to three, saving considerable hardware costs. The technology also reduces system-building complexity for Harland. All the servo drives and I/O on the main machine are interconnected by a daisy-chained Ethernet cable, saving wiring and space, as well as eliminating dozens of assembly operations. This has also allowed the drives to be fitted on one electrical panel, rather than the several used before.

The use of this technology has additional benefits for Harland customers. The ability of the network to mix and match motor technologies such as servos and steppers provides a very cost effective platform for meeting label application requirements. And the open connectivity of the resulting automation -- which allows the end user company to link to it via a factory network -- improves line efficiency and productivity.

Baldor’s single Ethernet Powerlink controller can handle a large number of devices on the network, including managing up to 16 interpolated axes simultaneously.

For more information, visit Baldor.