Tag Archive: measurement

Jun
09

Wireless Control Presentation – ACC 2014

OLYMPUS DIGITAL CAMERA

This last week I gave a paper presentation at the American Control Conference, Portland, OR. The topic of this paper was PID Control Using Wireless Measurements. I co-authored the paper with Mark Nixon and Willy Wojsznis. Below is a picture taken during the presentation. This paper presents a wireless PID controller, known as PIDPlus. The …

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Feb
24

Wireless Control – ACC 2014

The 2014 American Control Conference, ACC, will be held Wednesday through Friday, June 4 – 6, at the Hilton Portland & Executive Tower, Portland, OR. As noted on the conference web site, the ACC is internationally recognized as a premier scientific and engineering conference dedicated to the advancement of control theory and practice. Last year …

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Jan
20

WirelessHART – Discrete Measurement

702 Transmitter

Many manufacturers initially introduced WirelessHART field devices that were designed to support continuous process measurements such pressure, flow, temperature, and level. Also, WirelessHART transmitters are now available for analytical measurements such as pH. Recently you may have noticed that some manufacturers have introduced WirelessHART field devices for discrete measurement. For example, Rosemount has released the …

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Dec
09

Using Wireless Measurements In Control Applications

Using Wireless Measurements in Control

Wireless transmitters may be preferred in applications where new measurements are required since the cost may be lower than that associated with installing wired transmitters. However, there is a significant differences in the frequency and manner in which a new measurement value is updated by a wired transmitter vs. a wireless transmitter. Such differences must …

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Oct
14

Control Using Wireless Measurements

Control Using Wireless Measurements

During the initial development of WirelessHart we began researching how to address control applications that use a wireless measurement and/or wireless actuator. To extend battery life a wireless transmitter may be setup to communication the measurement value much slower than the update rate of a wired installation. Also, when the transmitter supports Window communications (as …

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Feb
25

Identifying Transmitter Problems

Standard PID Parameters

One of the most obvious reasons for poor control utilization is a broken or unreliable transmitter or sensor. As addressed in Chapter 3 of Advanced Control Foundation – Tools, Techniques, and Applications, if the control system is designed to be consistent with the international function block standard, IEC 61804, the status attribute is always communicated …

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Feb
11

Control Utilization

Pulp and Paper Mill Control Utilization

It can be shocking to examine control utilization in a plant where performance tools have not been installed and/or not used. For example, in the mid-1980s a control survey was conducted at a major pulp and paper plant where the control system had recently been updated to the latest distributed control system. At that time …

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Feb
04

Evaluating Control Performance

A plant operator is usually responsible for managing one or more process areas, with (potentially) hundreds of control loops and process measurements in each area. The operator’s job is made easier if the control loops in these process areas are in automatic mode and can compensate automatically for disturbances and maintain the operating conditions the …

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Jul
30

Boot Camp for New Employees

BookOutline

Courses required for an engineering degree are designed to provide the student with a sound technical foundation for work in industry. However, in most cases these courses do not address the terminology and common practices that an engineer must know to design, implement, checkout and commission a process control system. Universities can help bridge this …

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Jul
02

Mode – The Role of Status

Propagation of Status

As the ISA50 function block team considered how to improve plant operations through a more comprehensive implementation of mode in the control system, they realized it would be important that the control blocks, such as the PID, be designed to automatically take into account up-steam and downstream conditions that impact control operation. Thus, inputs and …

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