Information equals control.

Increasingly, real-time information control also includes the machine-level controls and materials handling control systems that manage automation in a factory or distribution center.

The reason is simple. 'The demand chain of orders has to be coupled with the supply chain right down to what's happening on your conveyors,' says John Nesi, director of commercial marketing, Rockwell Automation (414-212-5200). 'That requires real-time information from your control system.'

That is especially true as manufacturing and distribution move away from long production runs and full truck loads to product runs of one and parcel shipments.

'Everything has to be tracked by product code, by quantity, by where it's going, and by why it's moving,' says Steve Legg, president of Real Time Solutions, an FKI Logistex company (510-985-6300). 'The information flow is much more complex than it was in the past.'

But there's yet another dimension developing here. It's no longer enough to have access to that information within the four walls. The information now needs to be available to executives with broad supply chain responsibilities.

A three-tier system of information handling is emerging to provide that control.

The first tier is the machine and device level, where microprocessors, programmable controllers (PLCs) and PC-based controls manage materials handling equipment.

The second tier is the planning and execution systems, a layer of application software that includes enterprise resource planning (ERP), warehouse management system (WMS) and materials handling control systems (MHCS). The key element here is middleware that bridges the WMS and machine controls.

The final tier is the Ethernet communications network that ties together broader business management systems. That closes the loop between the factory floor and senior supply chain executives.

'What we're really talking about is a synthesis of controls, control software systems and real-time control,' says Bill Lydon, business development manager, Wago Corp. (262-255-6333).

Not long ago, users of automation chose between PLCs and PCs to run their systems, with very little in between.

Today, a system is likely to involve a combination of PLCs, reliable industrial PCs, and programmable microprocessors, depending on the tasks performed in a work zone.

'We used to think we were the PLC-killer,' explains Matthew Overmyer, marketing manager for Entivity Inc., a provider of PC-based control systems (734-205-5000). 'Now we connect with PLCs.'

In fact, it's hard to tell the difference between PCs and PLCs. 'Today's PLC is a logic solver, a motion solver, and it can manage fairly sizable packets of information over a network,' says Nesi of Rockwell Automation. 'Those used to be the domain of a PC and software package.'

The next generation of controller can also be programmed using open standards, allowing code to be saved in memory and used from machine to machine as with a PC.

'Our latest PLC has a 32-bit processor with 8 mgs of memory in a little package,' adds Lydon of Wago. 'It can serve up Web pages and send e-mail and FTP files.'

ARC Advisory Group has coined a new term to describe these evolving control devices: programmable automation controller or PAC.

'A PAC is an automation engine that can be programmed and move data, rather than a specific piece of hardware,' explains Craig Resnick, ARC's research director, manufacturing advisory services (781-471-1000). 'For that reason, a PAC might be found in an industrial PC, a traditional PLC with processing power, or in a programmable microprocessor embedded into a smart machine, such as a conveyor or sortation device.'

Distributing intelligence to the machine eliminates the need for a high-level PLC controlling that part of the system. 'In the past, we would typically have a PLC managing multiple machines and zones,' says Boyce Bonham, technology center manager for Hytrol Conveyor Co. (870-935-3700). 'That required a bigger processor and more programmers to program that PLC.'

And with distributed intelligence, users can take a modular approach to building their systems. 'You not only have a product with the controls to operate that piece already built in, you can actually plug these different modules together like Lego blocks to create a solution,' says Keith Anderson, principal engineer, Siemens Dematic (877-725-7500).

Whether a facility uses microprocessors, PLCs or PCs, that system of controls has to be managed to fill orders. Today, that falls to a materials handling control system (MHCS), a warehouse management system (WMS) for automated systems.

'The material handling control system is like an orchestra conductor,' says Jürgen Conrad, president and CEO of viastore systems (616-656-8876). 'The WMS knows that certain items are going to be picked by the automated system. The MHCS knows where that item is stored in the AS/RS; what crane will pick it; and how to balance the work load on the conveyors, sortation systems, palletizers and stretch wrappers.'

As it communicates with other systems, the MHCS also opens a window into operations for someone outside of the four walls of the plant or distribution center.

'You used to have a PLC telling the automation equipment what to do and a separate PC monitoring operations and diagnostics,' says Mike Kotecki, senior vice president, HK Systems (800-457-9783). 'That functionality has now been integrated into the equipment management system.'

That allows a DC manager to log onto the system from home over the Internet and see that a pallet is stuck on the conveyor. Then he can click on the pallet and drill down and see what products were loaded onto that pallet. Alternatively, the system can be programmed to automatically send that information to a maintenance team by page or e-mail and with much more detail than in the past.

'We used to tell the maintenance team that there was a problem in a specific zone,' Kotecki says. 'Now we can tell them that photo eye number 6 has been blocked for the past five minutes.'

Just as the line between traditional PLCs and PCs is blurring, so is the line between WMS and material handling control systems. Companies like HK Systems and SK Daifuku (800-253-1000) are creating supply chain execution systems that can combine equipment management and warehouse management functionality in one integrated package.

'We believe there's an advantage to building the major automation drivers into the WMS system,' says Jim Allred, vice chairman, SK Daifuku. 'When you do that, you eliminate the need for a materials handling control system in the middle. Now, you can control inventory, order management and fulfillment, and the automated materials handling system from the warehouse management system.'

Real time isn't the only buzzword applied to materials handling controls these days. The other is networking—creating an information bridge from the shop floor to the executive suites.

With networking, the cells of automation across a factory or warehouse can now be tied into the information management system that runs the business.

'Networking means someone doesn't have to walk across a 1 million square foot facility from the control room to see if a light is on,' says Bradford Beale, general manager of industrial application systems for Comtrol (763-494-4100).

It also means that a supply chain executive doesn't have to walk into the warehouse to find out how many orders per hour are being picked. That information can now be accessed in real time from an ERP system.

Networking used to be done through proprietary systems created by PLC and PC-based control providers. Today, the Ethernet network that also connects desktop computer, printers, faxes and copy machines in the front office is becoming the standard.

Standardizing on Ethernet protocols results in faster implementations and lower engineering and maintenance costs. It also provides a common platform for facilities with a mix of new equipment and legacy systems that are still productive in their application. Using Ethernet protocols, all of those systems can communicate together.

'That allows a user to migrate into new technology without having to throw out all of their older equipment all at once,' says Beale.

And that really is key to gaining real-time control.

Click on the icon to read more about PACs.

Click on the icon to learn more about materials handling control systems.