By Rick Pedraza, Digital Managing Editor, and Joe Feeley, Editor
SINCE WE LAST did a roundup on programmable controllers, not much actually has changed. The market for PLCs still is expected to grow at a annual rate approaching 5% through 2008, despite declining prices.
And the landscape continues to blend. “The term ‘PLC’ no longer stands only for logic control and programmability,” reports ARC senior analyst Himanshu Shah. “Communications capabilities, large memories, and fast CPUs have turned the PLC into a universal automation component that fits all applications.”
Nano PLCs are finding new ways to address the relay replacement market, says ARC, while micro PLCs ride on the health of the machine tool market.
It’s pretty clear that industrial OEMs still lean toward PLC-based, application-specific solutions. The PLC is a standard component, virtually an off-the-shelf component these days, and its programming techniques remain well-understood and reassuring to system designers.
For a while, many industry pundits saw PC-based controls wiping out the PLC control model. That possibility is a goner. PLCs today contain PC-based technologies that contribute to PLC functionality. A look at this round-up confirms the availability of connectivity and open standards functionality in PLCs and motion controllers--functionality once found only in PCs.
ARC reminds that China, Eastern Europe and Russia, India and Brazil are rapidly developed regions with populations that demand automobiles, processed food and beverages, infrastructure facilities, and appliances. All industry sectors are growing in response to the domestic demands in these regions.
We now often hear that PLCs are such a commodity item that suppliers often don’t know the end use of the nano and micro-PLCs that they sell through distributors.
Product Round-up: Programmable Controllers
Learn from the Master
RMC70 series of one and two-axis motion controllers support Ethernet communications through an interface that can be used to download motion control programs from a master controller such as a PLC or industrial PC. It has speeds of 10/100 Mbps with full or half-duplex operation along with auto-negotiation and auto-MDix crossover detection. Delta Computer Systems; 360/254-8688; www.deltamotion.com
Controller Packs It In
PACSystems RX3i controller provides application portability across multiple hardware platforms, allowing OEMs and end users to choose the exact control system hardware that best suits their needs. The system supports a range of I/O including discrete, universal analog, high-density analog, high-speed counter and motion. GE Fanuc; 434/978-5000; www.gefanuc.com
320 controller offers automatic startup sequencing, speed control and process control for one or two-valve steam turbines. It offers users flexible digital and analog input/output (I/O) configuration, control options, and Modbus serial data communications. The controller has megawatt cascade control; load limit control; and inlet, extraction/induction and backpressure control combinations. Selectable real-time trending and recording are available. Triconex; 281/709-1234; www.triconex.com
Smart and Powerful
FC5A MicroSmart PLC has built-in 100 KHz high-speed counters, 32-bit registers, floating-point math, and downloadable system firmware. Up to 520 local I/Os can be configured in the system. It has 64 KB programming capacity, and a wide array of timers, counters and data registers. IDEC; 800/262-IDEC; www.idec.com
MDrive42 AC-powered integrated motor and driver plugs directly into electric outlets and is suited for brushless motor control applications in robotics, assembly, semiconductor manufacturing, packaging, engraving, inspection and pick-and-place. An optional internal encoder, planetary gearbox and rear control knob are available. Intelligent Motion Systems; 860/295-6102; www.imshome.com
Face Your Control Issues
SoftMotion Controller provides a soft motion interface between motion driver software and distributed intelligent drives. The controller runs on LabView Real-Time ETS for Copley CANopen drives and LabView Real-Time RTX for Ormec ServoWire drives. The driver interfaces between the controller and the development environment on Windows 2000/XP. Engineers program in LabWindows/CVI, Visual Basic and C programming environments. National Instruments; 800/258-7022; www.ni.com
CP570 with Celeron 300 is an x86-based, high-performance CPU that can be a complete control or remote I/O system for the expansion of industrial PCs and controllers. USB and 10/100 MBit Ethernet are integrated as standard. Compact flash cards store application programs and related data. Optional real-time Ethernet for motion and I/O is available. B&R Industrial Automation; 770/772-0400; www.br-automation.com
750-841 Ethernet-based programmable controller has a built-in IP filter to protect against unauthorized access. Configuration is via web pages in the controller. When the security option is on, only certain nodes can communicate with the controller. It has a multi-tasking 32-bit CPU with a real-time clock, 512 KB of program memory, 128 KB of data memory, and 24 KB of retentive memory. Wago; 800/din-rail; www.wago.com