It's not often you see the price leader in a market snare the role of technology leader. Yet this is the case with PLCDirect's (Cumming, Ga.) introduction of two new control platforms for the Microsoft Windows CE operating system (OS).

The WinPLC and RuntimePC combine PC-based control software, Ethernet ports, PLC I/O, and flat-panel display hardware with Windows CE. This real-time, small footprint, diskless OS was designed from the ground up for embedded systems. (See box next page, for additional Windows CE information). WinPLC builds on PLCDirect's DL205 programmable controller family; the RuntimePC platform is a diskless Windows CE industrial PC.

From its humble beginnings as the "world's smallest PLC company," PLCDirect has expanded its sales and warehousing operations to a new four-story facility north of Atlanta. Founder and president Tim Hohmann credits his company's success to being, "an underdog with a winning attitude." This winning attitude built a "federation" of companies dedicated to highest-performance solutions at lowest costs. PLCDirect markets and sells products from the federation companies through its 600-item catalog.

The development of the new Windows CE-based controllers and software required cooperation and teamwork among the following federation companies:

• Host Engineering—WinPLC;
• Think & Do—Windows CE control software;
• PLCDirect—DL205 I/O and PLC rack.

These products, along with the RuntimePC manufactured by Ann Arbor Technologies, merge automation with commercial PC technologies.

The development cycle for a proprietary automation product is typically three to five years. This significantly reduces useful produce life, at least in terms of current technology implementation.

One of the strongest arguments for open PC technology in automation is to deploy commercial developments as they occur, rather than three to five years down the road. This has resulted in the great PC vs. PLC debate.

With Windows CE, both PCs and PLCs hold merit, depending on the application. Windows CE control software, running in realtime on a PLC, can connect to existing I/O devices while still providing open access to standard networking and software. Windows CE application software running on a diskless industrial PC combines real-time control and robustness with an intuitive human-machine interface.

Federation companies have implemented Windows CE solutions using Ethernet as the communication backbone. Ethernet was chosen because it, also, is a commercial standard with highest performance for lowest cost. (Driver cards are available for $75.) The WinPLC CPU communicates with DL205 I/O modules over the backplane, but offers Ethernet and serial ports for PC and operator interface communication. The RuntimePC includes a built-in Ethernet hub with three ports to talk to PLCDirect I/O bases and one port for network communication.

Think & Do software, which is available in Windows CE and NT versions, provides the control engine for both hardware platforms. Programmed with flowcharts, the software integrates logic control, motion control, and HMI.

Windows CE addresses barriers to PLC- and PC-based control. Its small footprint and reduced hardware requirements lower system costs. It is realtime and robust for industrial applications. It leverages commercial developments for software and communications and is portable across multiple platforms, helping bridge the PC and PLC worlds.