Out of sight better not be out of mind, at least when it comes to machine I/O.
Whether they’re inbound sensor data or outbound actuator commands, real inputs and outputs are an important part of what makes an automation scheme work, even if what’s being controlled is a good distance away. In such cases or when otherwise beneficial, there’s remote I/O, the distributed digital and analog I/O modules gathering signals in remote locations and connecting them to a central controller.
Long used and familiar, remote I/O is undergoing changes and innovations. It’s getting smaller, faster, customizable and intelligent.
One OEM taking advantage of advances in remote and local I/O technology is Husky Injection Molding Systems. The Bolton, Ontario-based company’s machines make many of the preforms that become PET plastic beverage bottles.
The company leverages networked I/O and many other technology innovations in its new designs (Figure 1). The result is that the latest Husky machines have cut materials costs by hundreds of thousands of dollars annually, in line with an industry-wide trend to reduce raw material use. These machines also have provided productivity and cycle time gains of up to 12%, according to Roman Pirog, director of development engineering at Husky.
As part of these improvement efforts, the company is always adding functionality to its machines and so always requires more I/O and I/O modules (Figure 2). The challenge is that the machine footprint and the footprint inside cabinets are fixed. The solution is to deploy higher-density I/O technology, so it’s possible to fit many more I/O points in the same or smaller space, explains Endel Mell, electrical design team leader.
The use of distributed and networked EtherCAT I/O brings other benefits, he adds. The availability of diagnostic tools, for instance, makes it possible to pinpoint problems with both the equipment and the end product. Also, the technology allows signal oversampling because it supports rates of up to 100,000 samples per second. Such advances minimize control loop delays, increase control accuracy and maximize uptime, all of which are valuable to Husky and its customers.
For its machines, Husky uses products from Beckhoff Automation and has been doing so for over 15 years. For instance, one of the company’s latest machines, finalized at the end of 2013, includes a range of EtherCAT-based I/O terminal modules from Beckhoff.
Husky’s global array of facilities manufacture injection molding machines, hot runners, molds and integrated systems. It has thousands of machines in the field.
Remote build to suit
For medium- to large-sized machine builders, Beckhoff has introduced an I/O system that plugs into customer-specific circuit boards. “It’s a remote I/O concept that’s been customized to a fine level of detail,” says Kurt Wadowick, Beckhoff I/O and safety specialist.
Also read: 2015 State of Technology Report: I/O Systems
Thus, the modules will be tailored for a given set of relays, process transmitters and other specific I/O. It can include anything currently available in the company’s EL terminals. The resulting circuit board will consequently have everything needed for a given machine. The board can be designed by the customer or Beckhoff.
The benefits of this approach are simpler wiring, reduced assembly errors and easier and faster repeat assembly, says Wadowick, who assures there also will be lower overall system cost, although the components of the customized solution may be more expensive than the corresponding discrete components. An added plus is that the new customized I/O modules are smaller by about 40% when compared to Beckhoff’s EL equivalent.