Heart of the Network

"Because so many control and automation applications need determinism, the Ethernet-based media access controller (MAC) layer in FPGAs and other processors can be modified to add more timing blocks to achieve the determinism required," says Jason Chiang, senior strategic and technical marketing manager at Altera. "This is the beauty of FPGAs. At the physical, printed-circuit-board (PCB) level, you can use one card to run multiple fieldbus protocols, such as Profinet, EtherNet/IP or SERCOS III. So we've been seeing a shift to more programmable logic and industrial networking on FPGAs. We make these for customers like Rockwell Automation and Siemens, and then they add their secret sauce to the Ethernet MAC hardware and run their software stack on it."

Altera makes microprocessors, such as its Cyclone IV SoC FPGA, and industrial networking kit (INK) for developers (Figure 1). In mid-October, it also announced a new class of SoC FPGA with a full ARM core processor on it.

We're likely going to see three or four times the amount of Ethernet we have now because the chips and software are fast and cheap enough to handle it, and because they can run over copper, fiber or wireless, depending on the application's environmental needs," says Mike Miclot, marketing vice president at Belden. "This will mean more real-time control and safety integrity level (SIL) functions at the same time, SCADA combined with security and surveillance, and video streaming in a lot more applications."

This past January, Advanced Micro Devices (AMD) introduced an embedded G-Series Accelerated Processing Unit (APU), which is small and fast enough to operate at 5 W in a headless, embedded PC form factor that runs Linux and can accept high-definition video (Figure 2). It can network everything from sensors to robots via Ethernet, monitor and network plant-floor operations, effectively replace many PLCs, and even has virtualization hooks to optimize the performance of a virtual operating system or "hypervisor," according to Dave Jessell, AMD's embedded enterprise development manager. "Software usually gets most of the limelight, but it's the hardware standards these microprocessors are based on that provide the foundation for software developers to do industrial applications," Jessell explains. "G-Series APU is able to calculate algorithms closer to real time, which allows it to achieve better control and efficiency, and connect many industrial devices as thin clients to a virtual server."

Many machine builders demand that their control and automation suppliers provide components with more-open networking, so the end users of their machines won't be constrained by proprietary hurdles, adds Bob Ferrar, director of the intelligent systems group at Intel. "As a result, some suppliers are moving from proprietary and non-standard ASICs to more open ones based on standards like IEEE 1588 and others," he says. "Sometimes, PLCs also can't talk to each other very well, and so they might need an FPGA with protocols loaded on it to translate between them. However, this can cause speed to become an issue, which might be acceptable for an application cycling at 500 ms, but not for a robot arm running at 50 ms."

Simplify and Combine Networks

Just as more sophisticated software in the background allows users to type in less code and do more point-and-click programming, more capable and widely distributed CPUs are simplifying plant-floor systems and networks, and making it easier to use and service them.

For instance, to coordinate the data and control needs of an expanding woodyard operation at Packaging Corp. of America (PCA) in Valdosta, Ga., its two system integrators recently decided to combine two separate control systems (Figure 3). This operation includes a woodchip stacker-reclaimer from Bruks Rockwood, which uses Allen-Bradley controls and communicates via EtherNet/IP. PCA works with system integrator Electric Machine Control (EMC) in Birmingham, Ala. However, the yard's log-handling cranes, debarkers and conveying systems are supplied by Fulghum Industries in Wadley, Ga., which employs other controls, including PACs from Opto 22. This equipment is integrated by Advanced Control Solutions (ACS) in Marietta, Ga.

To interconnect the two control systems for better data throughput and coordination of operations, the two integrators decided to maintain Opto 22's local, distributed control system, and use the Valdosta plant's Ethernet network. The Opto PAC could talk directly to the A-B PLCs because Opto 22 recently added support for EtherNet/IP.

"Once enabled, our I/O can be added to Logix platforms, and communicate with PLCs with no programming required," says James Davis, Opto 22's senior application engineer. "Also, Opto 22 controllers can serve as slave devices or adapters in the Logix architecture." Likewise, ACS's systems engineer, Sean O'Rourke, worked with EMC to interface to the A-B PLCs via fiberoptic connections, which provided a reliable, high-bandwidth, high-noise-immunity, long-distance physical network.

"Configuration and setup was simple," O'Rourke says. "We only needed to define the assembly instances, assign inputs or outputs, and specify the number of bits for how long each instance was going to be."