Top 20 'must-know' terms in control & automation

Control Engineering Staff -- Control Engineering, 1/1/1999

With the year 2000 right around the corner, here are Control Engineering's picks for the most significant words of automation and process control.

Advanced control—Process control strategies beyond PID loop control, such as feedforward, dead-time compensation, lead/lag, adaptive gain, neural networks, and fuzzy logic.

Brushless motor—A synchronous three-phase motor that uses electronic commutation for current switching among the phases. Depending on the current waveform and torque characteristics, it is commonly called brushless dc when a trapezoidal current/torque format is used and brushless ac (or just simply brushless) when a sinusoidal current/torque format is applied.

Fieldbus architecture—Control architecture that uses digital, serial, multidrop, two-way communications between and among intelligent field devices and control/monitoring systems.

Human-machine interface— Method of displaying machine status, alarms, messages, and diagnostics, often graphical display on a personal computer, providing operator feedback.

IEC 61131—International standard for machine control programming tools. Part Three provides five languages with standard commands and data structure, allowing changes to programming software with less extensive training.

Intelligent field devices—Microprocessor-based devices capable of providing multiple process variables, device performance information, diagnostic results, and execution of assigned control functions.

Intelligent I/O modules—I/O module that provides intelligent, on-board processing of input values to control output values, bypassing the PLC or control controller for routine decision making.

Internet—Global collection of industrial, commercial, academic, government, and personal computer networks that exchange information.

Interoperability—When products are replaceable by a similar product from another vendor.

MES—Manufacturing Execution System delivers information enabling optimization of production activities from order to goods. It guides, initiates, responds to, and reports on plant activities.

Microsoft Windows Operating Systems—The most widely used operating systems for personal computers. Microsoft NT is a desktop and server package for enterprise-wide applications. Microsoft 95 is a self-contained operating system a built-in and enhanced version of DOS. Microsoft CE is a compact version of Windows for handheld PCs and embedded devices.

Object-oriented software—Software that uses and reuses parcels of code to build applications modeled on object techniques including COM/DCOM, Java, and CORBA standards.

OLE for process control (OPC)—Object linking & embedding (OLE) that treats data as collections of objects to be shared by applications supporting OLE specifications. OPC provides extensions to OLE to support process control data sharing.

Open controller—Controller that looks like a traditional PLC but is a PC operating in a Windows environment with software control.

Open systems—Hardware/software designs in which a degree of interchangeability and connectivity give users choices. Systems complying with the seven layers of the ISO-proposed open-system interconnect, 7-layer model.

PC control—Software-configured control strategy using standard personal computer hardware and software.

PID (Proportional, integral, derivative control)— An intelligent I/O module or program instruction which provides automatic closed-loop operation of process control loops.

Programmable Logic Controller(PLC)—A solid-state control system with user-programmable memory for storage of instructions to implement specific control and automation functions.

S88—An international standard developed by ISA that uses object-oriented concepts to define terminology and models for batch control processes.

Soft logic—Controller is the software which can run on a variety of personal-computer form factors. Most useful in applications requiring high data collection and processing as well as communications to other networks.