Pneumatics Integrates With Electronics

Current trends for industrial pneumatics show expansion into more electronics as well as integration with them.

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"Expect it (the integration) to continue to improve," predicts Sachin Kambli, a product-management specialist with automation components vendor Festo Corp. (www.festo.com), Hauppauge, N.Y.

Thomas Dwyer agrees. He notes, "Increased interchangeability and modular integration between pneumatic and electromechanical actuators is a current trend." However, end-users "increasingly expect a full range of automation drives and controls that are interoperable and modular with one another," states Dwyer, application support manager for supplier Bosch Rexroth Pneumatics (www.boschrexroth-us.com/brp), Lexington, Ky.
 
Last fall, Festo debuted a new controller that could improve end-users' operations. Frank Latino, Festo product manager for valve terminals and electronics, calls it "a pretty sophisticated PLC (programmable logic controller)." Dubbed formally the CoDeSys Embedded Controller CPX-CEC, it contains programming for the International Electrotechnical Commission (IEC) 61131 Standard. The controller can accommodate communications protocols CANopen, DeviceNet, EtherCat, EtherNet/IP, Interbus, Modbus TCP (transmission control protocol), Profibus and Profinet.

Latino explains the reason for a PLC from a pneumatics company. "Suppose you buy a PLC from vendor ABC. You'd program the PLC, and that would be located in a box somewhere. You'd then need to run a cable to the device. And you'd still have to mount a valve manifold on the machine." With the Festo technology, end-users can mount a small human-machine interface (HMI) on the machine and then program it directly, he remarks. Also, with CoDeSys, he says, users have an unlimited number of tag names, can use libraries for other 61131 controllers, or can import the code of other 61131 controllers into the PLC.

But pneumatics plus electronics goes beyond command. "We're looking at integrated control and diagnostics in the field," Latino relates. For example, the Festo Maintenance Tool can be used as an integrated information technology (IT) service. "We can drill right into the [control] valve manifold and look at problems—and can find which individual point presents the problem," he explains. Because of the tool's embedded electronics, "the end-user has the ability to do this [field-level] diagnostics on any point. And we don't limit the number of valves on the manifold."

Obtain diagnostics

Electronics make device-level diagnostics work, Sachin emphasizes. But to make any level of diagnostics work better, newer electronics technologies obviously must allow better communication. To facilitate that, late last year, Bosch Rexroth incorporated SERCOS III—the third-generation Serial Real Time Communication System that works over Ethernet—in pneumatic valve manifolds. "This enables pneumatic devices to be directly controlled in one fieldbus network with highly synchronized servo-motor applications, rather than having separate networks for each," Dwyer explains. The product also features the safety aspect of SERCOS III to the valve manifold itself, something's that not an option in most other bus protocols, he adds.

In the manifold itself, pistons need monitoring. For that, Bosch Rexroth recently launched a solenoid dump valve with monitoring sensor. The device tracks piston status. "This delivers increased condition monitoring to the machine controller," Dwyer states.

Besides the pneumatics-electronics coupling, though, there's also a lot of integration of pneumatics and electric drives, Festo's Latino notes. He explains that some valves might be moving pneumatically on the X-Y axis, "but maybe the Z-axis motion needs very precise positioning." The solution he suggests: "a hybrid where Z-axis motion control might be electric and the X-Y motion might be pneumatics."

To help fill this void, Bosch Rexroth also recently launched a range of electrical slide units that are dimensionally interchangeable with pneumatic equivalents. "This enables machine designers to optimize the cost-to-performance ratio of a multi-axis system and, for future needs, enables the end-user to reconfigure at minimal cost and complexity," Dwyer comments. That's pushing in the right direction.

C. Kenna Amos, ckamosjr@earthlink.net, is an Automation World Contributing Editor.

Festo Corp.
www.festo.com

Bosch Rexroth Pneumatics
www.boschrexroth-us.com/brp

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