From the Editors of CONTROL
First, there were manual controllers, then mechanical, electromechanical and multi-loop models. Today you see single and multi-loop controllers with a higher level of functionality using PLCs, PCs and DCSs in a compact package. According to the Electronics Industry Market Research and Knowledge Network, the 2005 worldwide market for industrial electronic temperature controllers totaled $835.8 million. However, both the European and North American markets expect to see a decline through 2010. These two very mature markets will suffer from a combination of forces, including declining prices, relocation of OEMs and end users to emerging areas, such as China and Latin America, and competition from other means of control such as PLCs, PCs and DCSs.
However, if you’re in the market for a loop controller here are some of the parameters you need to evaluate before purchasing—cost, DIN-rail mountability, size, software support, data logging and trending, fuzzy logic, multi-loop control, PLC-based control, PC use in factory automation, and communication networking.
DIAL UP YOUR MACHINES
Master Control Module is used with the Modular Controller Series to allow users to create a “virtual HMI,” allowing machines to be controlled and monitored via any networked PC with a standard web browser. Facilities can access and control any connected device in a system, including PLCs and motor drives. The multi-zone PID controller can also log system data directly to CompactFlash in Microsoft Excel-compatible CSV files. These files can be retrieved via USB or the web server. Red Lion Controls; 717/767-6511; www.redlion-controls.com
i-Series masters/controller combines web-enabled controllers, panel meters, transmitters and signal conditioners, whch enable users to monitor and control a process through a web browser anywhere in the world. Using the iSeries with a heater, for example, a technician can monitor temperature, change alarm points, turn off the heater, and make other modifications without special software. Omega Engineering; 203/359-1660; www.omega.com
Model 555 ¼-DIN controller handles flow proportional control, residual control, compound loop control with lag times, and dechlorination with sulfur dioxide in water and wastewater industry. The front panel is NEMA 4X-rated for protection from water and corrosion. All menu prompts are provided in plain English, and set with large, back-lit keys. Moore Industries International; 818/894-7111; www.miinet.com
BOILER CONTROLS AT THEIR BEST
SteamPAK series of boiler controllers brings boilers back to their design efficiency, and can save fuel consumption as well as electricity. They come ready-to-use with pre-loaded control strategies. Each SteamPAK comes with dedicated installation and start-up instructions that describe how to connect the field instruments, and use the boiler-specific displays to start-up a boiler. MicroMod Automation; 585/321-9202; www.micromodautomation.com
PROCESS DISPLAY MADE EASY
Model 32H8 1/8 temperature and process controller has a text display for easy configuration of the controller. When accessing the controller, users find that every parameter is accompanied by a scrolling text message that describes its function. Scrolling alarm and event messages can alert an operator of a change in plant conditions. These messages are customized with a PC tool. Eurotherm; 703/443-0000; www.eurotherm.com/3000
STORES UP TO 32 PROGRAMS
IPC5000 programmer/controller has two loops of program/control with a typical accuracy of ±0.10% and stores up to 32 programs with a total of 800 segments. Two universal analog inputs, two analog outputs, 12 digital inputs, and 12 digital outputs enable IPC5000 to be used in complex process control applications, including chemical batching and furnace control. Honeywell; 215/641-3798; www.honeywell.com
Control Microsystems offers the SCADAPack 350 and the SCADAPack 357 remote terminal units (RTU) providing PLC functionality for use in SCADA applications. These flexible, small-footprint products combine 32-bit processing with high-speed LAN and USB communications and advanced power-saving features. They come with an integrated power supply, 12-24DC converter, analog and digital I/O, serial communication and turbine flow meter counter inputs, Modbus TCP- and UDP-based Ethernet and DNP3 protocols. Control Microsystems; 888-267-2232; www.controlmicrosystems.com