Back in 2001, an ARC Advisory Group (www.arcweb.com) study said PLC suppliers were worried because changes in communications and computing technologies and the rise of industrial PCs were threatening the future of PLCs.
ARC may have missed the mark there. But in its latest study, "PLC Worldwide Outlook, Market Analysis & Forecast Through 2006," ARC says the PLC market will revive from the doldrums of 2001, is growing rapidly, and the industrial PC is not a threat. This report is much more in line with what is actually happening in the market.
Following is the market...the vendors' side, anyway. We'll show you what's new in this first of three installments on the subject. The next two segments will be web-published the weeks of October 20 and 27.
Zen Master Goes Anywhere
The compact ZEN nano controller measures 70x90x56 mm and installs in almost any location. It has up to three I/O expansion modules that can be added to any CPU for a maximum of 34 I/O points. The CPU module has eight operating buttons on the front panel to enable programming in ladder view. Programs can consist of up to 96 lines of ladder logic with three inputs and one output per line, which allows simple control applications to be accomplished easily.
Embedded Computer Has Touchscreen
The QVGA Controller is programmable in C, has a touchscreen-controlled graphical user interface, and comes with a high-contrast 320x240 pixel electroluminescent or LCD graphics display. It has eight 12-bit analog input channels, eight 8-bit analog inputs, eight 8-bit D/A lines, 24 digital I/O, four high-current drivers, and two RS-232/485 ports. A built-in GUI software toolkit provides an easy way to design a graphical interface to monitor, control, or display system status, bar graphs, or text messages.
Computer-Based Controller Uses CE
The CX1000 series automation controller is designed for tasks requiring the computing power of industrial PCs. The system runs under Windows CE or XP. Modules are connected with each other via the 16-bit PC/104 bus. The basic unit consists of a CPU module and a power supply module. It can be pre-installed without a TwinCAT system, with a TwinCAT CE PLC, with TwinCAT CE NC PTP, or with the associated full version of the individual TwinCAT levels for PLC and motion control.
Motion Controller Handles 32 Axes
Automation 3200 NMotion SMC software-only controller offers 32 axes of synchronized motion control through one interface, expandable to 62 axes. It uses a distributed control architecture that enables it to maintain performance independent of the number of axes being controlled. This avoids the processing bottleneck caused by previous single-processor control architectures. Trajectory generation is done on the PC, which sends incremental position commands to an NDrive via the IEEE-1394 (FireWire) serial bus.
Modules Network PLCs
The H0-ECOM Ethernet communications module provides a 10 Mbit Ethernet link for PLC systems. It can be used for peer-to-peer PLC communication between two or more DirectLogic DL05/DL06 PLCs or between PLCs and PCs. The H0-PSCM Slave Communication Module allows any DL05 or DL06 to be networked to any Profibus-DP Master at baud rates from 9.6 KB to 12 MB, depending on network length.
Eight Is Enough
MultiFlex PCI Series controllers provide 1-8 axes of high-performance servo and stepper motor control in a half-length PCI-bus card. The cards have a 64-bit floating-point CPU, opto-isolation, matched twisted-pair signals, 60 digital I/O, 12 high-resolution analog I/O, and closed-loop stepper control. Libraries for C/C++, VB, and LabView are included, as well as the company's Motion Integrator Windows toolkit.
Entry-Level PLC Processors
Processors for the Q Series industrial automation platform include the Q00JCPU, which combines a power supply, processor and five-slot backplane into one compact unit; and the Q00 and Q01, which operate standalone or matched to motion and PC units mounted in the same rack. Options include I/O modules, 100 Mbit Ethernet, network redundancy, PID control, and IEC programming support. Applications include complex motion control up to 32 axes.
Mitsubishi Electric Automation
Open Controller Runs Linux
The SixTrak IPm Open DCS controller is built on the Linux platform, which provides open access to users. It has five Ethernet and three serial ports, uses standard ISaGRAF IEC 61131-3 programming tools, and has a Linux web server that runs web pages created with any standard HTML development tool. Applications include process control, supervisory control and data acquisition, and distributed control systems. For most applications, no knowledge of Linux is required because the embedded Linux platform is transparent.