More with less, fewer, and smaller

10/08/2013


Smarter, more powerful devices combine functions 

There are many control innovations today that reduce the space required for control cabinets and machine footprints. Miniaturizing control devices and other industrial electronics has been a major driving force in this regard. For example, the power of embedded PCs continues to advance with powerful multi-core processors available, up to an Intel Core i7 2715QE 2.1 GHz quad-core CPU. With this kind of processor power, a small embedded PC that already serves as a machine’s PLC can also double as a motion controller, HMI processor, communication gateway, and more. This can help machine builders and manufacturers reduce the amount and variety of hardware they must equip on their machines.

When a powerful embedded PC is paired with the right software, it can easily handle complex motion control with numerous coordinated axes. It is also possible to do a great deal of multi-tasking with this kind of device by adding multi-PLC functionality, HMI, standard PC functions, and more, all in one box. This eliminates the need for several separate hardware devices that had been used in the past, shrinking machine footprint as a result.

Modern I/O technology has added capabilities that can handle digital and analog data acquisition functions while providing a range of special functions for various kinds of measurement, monitoring, safety, and even small drive technology. Amplifiers for servo motors up to 4 A are now available in DIN rail-mountable 12 mm wide enclosures. This kind of space saving is multiplied when applications require more axes of motion. For example, an application with five axes of motion within that power rating will take up only 60 mm of width in the electrical cabinet. Similar I/O solutions are available for stepper and dc motors. Taking direct signal measurements at the I/O terminal can reduce the number of transducers needed to monitor electrical data. These devices can operate with supply networks up to 500 V ac, 5 A, supplying power measurement statistics and diagnostic information to plant engineers.

Modern safety hardware also comes into play in saving space—integrated safe I/O systems can provide machine safety functionality for features such as e-stops, light curtains, protective doors, two-hand control, safety switching mats, safe drive functionality, and much more. This technology doesn’t require an isolated safety controller with its own network, software, and infrastructure—the safety I/O terminals easily can be added alongside standard I/O terminals and connected to a standard higher level controller.

Matt Lecheler is a motion specialist for Beckhoff Automation.



Jonas , , 11/08/13 03:55 AM:

Personally I believe another important way to reducing cabinet size and footprint is to use fieldbus technology for sensors and actuators instead of 4-20 mA and on/off signals. By using fieldbus, you can put as many as 16 devices on a single pair of wire, taking the place of on average 3 signals per device (48 signal wires replaced by one pair of wires). Perhaps only 10 devices will initially be installed per fieldbus, but it is still a dramatic reduction in the number of cable pairs, terminal blocks, and most importantly I/O cards that results in less cabinets and footprint. Moreover, since all signals are marshaled in software, marshalling cross-wiring is eliminated. They call it “virtual marshalling”:
http://www.fieldbus.org/images/stories/technology/aboutthetechology/overview/fieldbus_brochure.pdf

By using PROFIBUS-DP for motor controls such as variable speed drives (VSD), motor starters, and MCC, the need for relays and AC signals in the cabinets can also be reduced. This is over and above massive cable and I/O card savings.
http://www.ceasiamag.com/article-6631-thedigitaldrive-LogisticsAsia.html

Combining FOUNDATION fieldbus for process control and PROFIBUS-DP for motor controls is another way to significantly reduce the number of components and consequently, the space needed in the cabinet.

Using real-time digital communication networks all the way to the transmitters and valves also enables more effective intelligent device management (IDM) software part of the asset management system for device diagnostics, calibration trim, and configuration/setup. This enables more effective planning of daily maintenance and scheduling of turnarounds. Learn more:
http://www.eddl.org/DeviceManagement/