Top 20 ‘must-know’ terms in control & automation

By Control Engineering Staff January 1, 1999

W ith 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.

The Five ‘Hot’Control EngineeringTerms:Advanced controlBrushless motorHuman-machine interfaceOpen systemsS88

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.

Control Engineering staff