Invited Speaker

Terry Blevins

Emerson Process Management

PID Advances in industrial control


Major advances that improve control in the process industry have been made over the last ten years in the basic PID technology of modern distributed control systems. This paper addresses the impact that international standards have on control implementation and the tools utilized in industry for monitoring and commissioning PID control. Examples are used to illustrate how new technologies, such as model switching for process identification, have allowed manufacturers to introduce a new level of ease-of-use in tools developed for on-demand and adaptive tuning. This paper discusses PID modifications that improve the speed of recovery from process saturation conditions that are common in industrial applications. Also, details are provided on PID modifications that enable effective control with non-periodic measurement updates by wireless transmitters. Finally, prospective future directions for industrial PID controllers are sketched.


Terry Blevins has been actively involved in the application and design of process control systems throughout his career.  For over fifteen years, he worked as a systems engineer and group manager in the design and startup of advanced control solutions for the pulp and paper industry.  Terry was instrumental in the establishment of Emerson Process Management’s Advanced Control Program.  Terry was the team lead for the development of DeltaV advanced control products, including auto-tuner and adaptive PID, Fuzzy Logic, Neural Network and MPC controllers.   He is the Fieldbus Foundation team lead for the development and maintenance of the Function Block Specification and editor of the SIS Architecture and Model Specifications.  In this capacity, Terry is involved in the movement of Fieldbus Foundation function block work into international standards.  Terry is the US expert to the IEC SC65E WG7 function block committee that is responsible of the IEC61804 function block standards.  He is a voting member and chairman of ISA SP104- EDDL (Electronic Device Description Language) and is the technical advisor for IEC 65E USTAG.   Also, he is a member of USNC TAG (IEC/SC65 and IEC/TC65).    Terry authored “An Overview of the ISA/IEC Fieldbus”, Section 11, Standards Overview, Fifth Edition of Process/Industrial Instruments and Controls Handbook and coauthored four sections in the Fourth Edition of Instrumentation Engineer’s Handbook, Process Control and Optimization. He coauthored the ISA bestseller book, “Advanced Control Unleashed” and the book “Control Loop Foundation – Batch and Continuous Processes” and accompanying web site .  Terry has 45 patents and has written over 70 papers on process control system design and applications.   He regularly addresses process control and simulation topics in the blog . Terry received a BEE from the University of Louisville in 1971 and a Master of Science degree in Electrical Engineering from Purdue University in 1973.  In 2004, Terry was induced into Control Magazine’s Process Automation Hall of Fame.  Presently, Terry is a principal technologist in the future architecture team of Emerson’s DeltaV Product Engineering.