OR YEARS, MRCs HAD A STRANGE, ILLOGICAL FASCINATION with PC-based controls, and annually predicted the coming demise of PLCs. PCs will drive PLCs out of the market, the MRCs would say. All this was much to the amusement of machine builders, process equipment skid builders, end users and system integrators, who were buying PLCs as fast as they could. If PCs were being used for automation and machine controls, it was mostly for HMIs and certain motion control tasks.
PC-based controls barely put a dent in the huge PLC market, and everybody seemed to know it except the market analysts.
Finally, one of the chief proponents of PC-correctness, ARC Advisory Group (www.arcweb.com), appears to have given up. As is its wont, it created another three-letter acronym (TLA) called Programmable Automation Controller (PAC), said PLCs are now PACs, and it is now happy to predict that the sales of PLCs â¦ er, PACs â¦ will remain as strong as they always have, at about 4.6% annual growth, reaching $7.5 billion by 2008.
As for industrial computers, Venture Development (www.vdc-corp.com), predicts that they will continue to grow at 4.4% annually, reaching $537 million in the industrial automation, control and instrumentation marketby 2006.
In other words, there is nothing new in the machine control marketing research universe except another TLA.
The whole purpose of coining new TLAs, it seems, is to sell market research reports at $6,000 a pop. Although PLC vendors and machine builders already know as much about the PLC market as do MRCs, they buy the study just in case there is some new information they might have missed.
Some commodity pico and nano-PLCs now cost less than relays, commodity micro PLCs have the capability of the full-size PLCs of 10 years ago, and larger PLCs have become hybrid controllers with PC architectures, networking and web servers. You can buy commodity PLCs in the $100 range, especially with OEM quantity discounts. And if you pay $1,000 for a PLC, you get an outrageously powerful device. Going the other way, you can get a PLC on a chip and embed it in your machine.
No matter what you call them, PLCs are still the most reliable devices on the planet. That, plus their low cost, is why machine builders cling to them with such tenacity.
As you can see in the product round-up that follows, PLC vendors are keeping their products extremely competitive and up-to-date by using the latest hardware, software, and communications technology. This month’s Round-Up has PLCs and PACs with web servers, fieldbus networks, Linux operating systems, motion control functions and firewalls.
Although some may consider PLCs to be 40-year-old devices, they are as up to date as Kansas City. And, as we all know, “Everything’s up to date in Kansas City” (from the musical, Oklahoma!, which was revived last year on Broadway, with PLCs moving the scenery).
Brick-Style PLC Gets Off Its AS-iz
Enhancements to the MicroSmart brick-style PLC series include an AS-interface (AS-i) master module and an eight-point 120-VAC input module. The AS-i allows the PLC to communicate with slave devices such as sensors, actuators, and remote I/Os, using signals transmitted over the AS-i bus. The 120-VAC input module allows a user to apply 120 VAC directly into the PLC input card. This eliminates additional signal conditioning devices. Programming is via WindLDR version 4.5 software.
IDEC: 800/262-IDEC; www.idec.com
Pico PLC Performs Simple Control Functions
The Pico GFX-70 performs simple logic, timing, counting and real-time clock operations. It has an HMI, processor/power supply, and I/O modules. The LCD HMI can show text, date, time, custom messages and graphics, and allows operators to acknowledge fault messages, enter values and initiate actions. The integrated graphic display lets engineers program control and HMI functions with one software package, or with on-display buttons.
Rockwell Automation: 800/223-5354, ext. 1675; www.ra.rockwell.com
PLC Performs Motion Control
The 317T PLC uses Step 7 software, so only one program is needed for PLC and motion control on up to 16 axes. Motion control functions include positioning in absolute, relative, additive and superimposed operating modes, geared synchronous motion, electronic cam disc and cam, moving to a positive stop. It also has a measuring probe for print-mark correction.
Siemens Energy & Automation: 770/751-2477; www.sea.siemens.com
PLC Software Runs Linux
Version 4 of SoftPLC control is built on an embedded, real-time version of Linux. Enhancements include integrated firewall support, encrypted secure communications with the FTP Server, and remote command shell access to run programs, perform diagnostics, and restart the controller. Remote file access lets the software read/write production data to a remote disk.
SoftPLC: 512/264-8390; www.softplc.com
Controller Talks to Everyone
The PACSystems RX3i controller has a PCI-based backplane, Pentium 300-MHz CPU, and support for Ethernet, Profibus, DeviceNet and Genius networks. Power supplies can be deployed in single or multiple configurations to provide adequate power or redundancy in one rack. The system supports a wide range of I/O, including discrete, universal analog, high-density analog, high-speed counter, and motion. Tag-based programming is via Cimplicity Machine Edition software.
GE Fanuc: 800/GEFANUC; www.gefanuc.com
PC-Based PLC Has PID and Web Server
Type IPC FEC Standard PLC is based on PC architecture and has a built-in Ethernet interface, a web server, and an integrated PID controller module for closed-loop control functions. A front-panel plug-in sensor/actuator wire connector handles inputs, outputs and the power supply. Its FST Software PLC programming language has a STEP operation for programming sequences and basic arithmetic functions, and works via Ethernet or a web server.
Festo: 631/435-0800; www.festo-usa.com
Embedded PC Machine Control Gets on the Web
The System 2005 has a 500-MHz Pentium III processor, 64-MB DRAM, exchangeable Compact Flash, 10/100-Mbps Ethernet port, and a web server. For machine control, it has PLC functionality with 200-Î¼sec task classes, I/O modules, and insertable fieldbus modules. Software includes PLCopen motion library, Soft CNC and VNC Server. It can also be synchronized with the position loop controller in the company’s servo drive.
B&R Industrial Automation: 770/772-0400; www.ethernet-powerlink.org
DSP Gives PC Real-Time Control
The DT9842 high-speed data acquisition board has a dedicated DSP that processes data in real-time, providing a deterministic response and eliminating latency problems. With sampling rates up to 100 KHz, 16-bit accuracy, and uninterrupted data transfer, the board can transform a PC into a closed-loop platform for test and control applications. It has successive approximation A/D and D/A converters that simultaneously acquire and control eight analog input and eight analog output channels.
Data Translation: 508/481-3700, ext. 1544; www.datatranslation.com
Logic Relay Handles Simple Tasks
The Telemecanique Zelio programmable logic relay is suitable for applications that require greater flexibility than a simple relay, but are too small or simple to require the use of even the smallest nano-PLC. It has four or eight outputs, Modbus communications, and Function Block Diagram or Ladder Logic programming via the front of the module or by using ZelioSoft software. AC and DC versions are available.
Schneider Electric: 800/392-8781; www.us.squared.com
Low Cost Per Axis
RMC70 Series one or two-axis motion controller is priced under $1,000 per axis, depending on quantity. It has RS-232/485 serial communications, interfaces to MDT and SSI absolute-position transducers, and software for setup, tuning, programming and diagnostics; making it suitable for hydraulic, pneumatic and electric servo motion control applications.
Delta Computer Systems: 360/254-8688; www.deltamotion.com
SBC Has Pentium M Processor
General Micro Systems The P60x single-board computer is based on Intel’s Embedded Roadmap 1.8-GHz Pentium M Processor 745. The busless SBC measures 4x4 in., consumes 12 W of power, and can be used standalone or mounted to a single-slot carrier card such as 3U/6U CPCI, VMEbus, ATCA, or custom board. The M chipset includes the 855GME system controller, Hance Rapids I/O hub controller, and 82546 dual-gigabit Ethernet controller.
General Micro Systems: 909/980-4863; www.gms4sbc.com
Fieldbus Controller Goes Ethernet
Enhancements to the PFC Ethernet TCP/IP programmable fieldbus controller include increased data memory of 256 KB, a multitasking operating system, the ability to make online programming changes, and a real-time clock for time stamping and scheduling applications. Programs are stored in flash memory for recovery from power failure, eliminating the need for periodic battery replacement. It supports ModbusTCP and EtherNet/IP and interfaces to Microsoft .Net, Unix and Linux-based systems.
Wago: 262/255.6333 ext. 135; www.wago.com
Motion Controller Speaks Spanish
Commander PLC-based motion controller provides complete system diagnostics and programming in plain English and Spanish on a four-line by 20-character vacuum fluorescent display. It has dual logic power supplies, resolver with self-checking input on every press cycle, crank angle and speed readout, time-based brake monitor, and built-in motion detector and drift fault.
Pressroom Electronics: 800/937-4334; www.pressroomelectronics.com
Windows CE-Based Control Panel
The CP3xxT-Studio-IB control panel combines the functions of a PLC and an operator panel in one compact unit. It has dual processors for the control/HMI and I/O handling functions, 48-MB RAM of user program memory, 10/100BaseT Ethernet port, Entivity’s Studio flowchart software, a common OPC tag database, and Iconics PanelWorX software. Models are available with 6, 10 and 12-in. color TFT touchscreens. Programs and configuration data may be stored on a removable 32-MB compact flash card.
Phoenix Contact: 800/586-5525; www.phoenixcon.com
Motion Controller Fits on Half-Slot PCI Card
The ACR1505 is capable of operating four axes of servo or stepper motion control with four encoder inputs at up to 30 MHz, yet it fits on a half-size PCI card. It can be equipped with eight analog inputs for general-purpose inputs or for closing a servo loop, and has a 120-MFlop, 32-bit floating-point DSP, dual-port RAM, and 12 or 16-bit analog-to-digital converters.
Parker Electromechanical Automation: 707/584-2510; www.parkermotion.com
Web-Enabled Controller Answers E-Mail
Enhancements to the Model 5200 Blue Fusion automation controller include a built-in web server that enables users to monitor and control 192 I/O points and up to six axes of motion via the Internet. It sends alerts or production data via e-mail messages, and users can send an e-mail with customized instructions to modify the operation of the controller. The controller supports UDP, TCP/IP, HTTP, Modbus Master/Slave TCP, and DHCP protocols.
Control Technology: 508/497-0335; www.ctc-control.com
Single-Loop Process Controllers Handle Heaters
The SDC35 and SDC36 single-loop 1/8 and 1/4-DIN panel-mount process controls have three auto-tune modes: normal for general applications, immediate response for heated systems with fast-responding heaters, and stable for systems that involve a slower response heater design. Different PID values can be set for a specific temperature range to better control startup or ramping characteristics.
Yamatake Sensing Control: 866/736-7675; www.yamatakeusa.com
The QScreen controller, a C-programmable single-board computer is powered by an HC11 Motorola microprocessor and has a touchscreen-operated graphical user interface on a high-contrast 128x240 pixel display with a 5x4 touchscreen overlay. It features a real-time multitasking operating system, hundreds of pre-coded device drivers, and up to 1-M Flash and 512-K RAM. It commands eight 8-bit A/D lines, eight digital I/O lines including timer-controlled and PWM channels, and two RS-232/485 ports.
Mosaic Industries: 510/790-1255; www.mosaic-industries.com
PLC and CNC Share
IndraMotion MTX CNC controller works with current Microsoft operating systems and Ethernet TCP/IP is available. Numerical control and an integrated multi-tasking, IEC 61131-3 compliant PLC share the same hardware and VxWorks RTOS. The PLC executes 1,000 statements in 60 Âµs, and the CNC guarantees a maximum interpolation time of 1 ms when controlling eight axes. One controller can operate up to 64 axes using 12 independent CNC channels.
Bosch Rexroth: 800/438-5983; www.boschrexroth-us.com
Programmable RTU Melts in Your Hand
The Mini-VersaTrak mIPm RTU/Controller fits in the palm of your hand, yet has Ethernet, four serial ports and 26 discrete and analog I/O. It comes pre-loaded with open-source Linux and IPm firmware that provides automation, control and data acquisition functions. It also can be programmed using any mix of the ISaGRAF IEC61131 languages and C/C++. The controller is UL/CSA/CE rated for -40-70Â° C operation in Class 1, Div. 2 Zone 2 hazardous locations.
Sixnet: 518/877-5173; www.sixnetio.com
Embedded PLC Fits on a Chip
PLC-on-a-Chip single-chip programmable logic controller can be embedded into OEM products such as sensors, drives, custom controls and valve assemblies. It is programmed in ladder diagram and function blocks via PC-based EZ Ladder software. A complete development package is available.
Divelbiss: 800/245-2327; www.divelbiss.com
Adjustable Setpoint Controllers
Models SPC-701 and SPC-704 DIN-rail mountable controllers have one and four set points, respectively. The setpoints are independently adjustable, each having a form C relay output and a 0-10-V analog output. The controllers can be used with any 0-20 mA, 4-20 mA, 0-10-V, or 2-10-V analog input. To drive sensor inputs, 24-VDC excitation power at 150 mA is provided. Both controllers have a signal-averaging potentiometer that helps alleviate false detects.
Migatron: 888/644-2876; www.migatron.com
1/8 DIN Panel Meter Goes Both Ways
Model DIN-Bar is available in a vertical or horizontal mount, and has a bargraph with 51 segments that change colors, dim, blink and have pointers as commanded. It can be used as a standalone DPM, serial input remote display, part of a SCADA/DCS system, or a controller. The meter is NEMA 4X front-panel-compliant and measures 5-in. deep with screw terminal connector. It has RS-232/422/485, voltage and 4-20 mA I/O, and 10-A relay outputs.
Otek: 520/748-7900; www.otekcorp.com
Digital Panel Meter Plays Shallow Hal
The all solid-state Trident digital panel meter is packaged in a shallow-depth case that fits into tight spaces. It has a Type 4X, NEMA 4X, IP65 front panel with push-button setup and programming. The meter is calibrated to accept process voltage and current inputs, 100-Ohm RTDs, and thermocouples. Options include Modbus RTU communication, two relays to permit pump alternation, an isolated, linearized 4-20 mA output, and NEMA 4X enclosures.
Precision Digital: 800/ 343-1001; www.predig.com
Solid-state relays are available in 10 or 25-A DIN-rail mountable or 4-A plug-in models. DIN-rail mountable models feature a built-in integral heat sink and a red LED status lamp for easily viewing the contact status. A finger-safe cover offers protection from live input/output voltage wires or terminals. Plug-in models use the same mounting socket as industry-standard 2PDT relays, making them interchangeable with most mechanical relays.
AutomationDirect: 770/889-7876; www.automationdirect.com
PLC Still Fits in DIN
Newport Electronics The venerable i32 programmable controller is available in the 1/32 DIN size, and has thermocouple, RTD, process voltage and current inputs, built-in excitation for transmitters or other devices, and RS-232 and RS-422/485 serial communications. Its programmable display can change colors from green, amber, and red at any set point or alarm point. An external module connects up to 32 controllers to an Ethernet LAN and the Internet.
Newport Electronics: 714/540-4914 ext. 358; www.newportus.com
Zen Master Goes Anywhere
The compact ZEN nano controller measures 70 x 90 x 56 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.
Omron Electronics: 800/556-6766; www.info.omron.com
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 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 Twin Cat CE NC PTP, or with the associated full version of the individual TwinCat levels for PLC and motion control.
Beckhoff Automation: 952/890-0000; www.beckhoffautomation.com
Entry-level PLC Processors
Processors for the Q-Series industrial automation platform include 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: 847/478-2100; www.meau.com
Digital Gets Tough
Four digital modules for Compact FieldPoint and LavView Real Time control applicaitons include the cFP-CTR-500 and cFP-CTR-502 digital high-speed counter modules and the cFP-PMW-520 and the cFP-PG-522 digital output modules. These small, eight-channel digital modules can withstand shock, vibration, and wide temperature ranges. Applications include embedded machine control, industrial data acquisition, data logging, and in-vehicle applications.
National Instruments: 800/258-7022; www.ni.com
The PSS SB 3006 DP-S programmable safety system is divided into failsafe and standard sections, so it can perform safety functions safely and communicate via SafetyBus, while at the same time be connected to standard fieldbus and communications systems such as Profibus-DP and RS-232. The two sections communicate without affecting each other. The controller complies with EN 954-1 category 4.
Pilz Automation Safety: 248/473-1133; www.pilzusa.com