May
14
A panel on Future Perspectives of PID Control of was the highlight of the second day of the IFAC PID’12 conference. The panel chairman was Professor Karl Astrom who is widely known throughout the control community for his many contributions in process control. Willy Wojsznis was the speaker on the panel from Emerson. The short …
May
07
On the second day of the IFAC PID’12 conference, the paper that Dan Coyne, BP, and I wrote Improving PID Recovery from Limit Conditions was presented in the poster session. The paper addresses the performance of the PID under startup or during normal operation when the PID output becomes limited. Common techniques that have been …
Apr
30
Willy Wojsznis is the primary author of a paper on Intelligent PID Product Design that was written for the IFAC PID’12 conference. The paper was scheduled to be presented in the first session of the conference on Wednesday, March 28, 2012. Unfortunately, Willy was delayed in getting to the conference. Thus, since I was a …
Apr
23
Field experience using WirelessHART in control applications may be summarized in the following manner: WirelessHART measurements may be used in closed loop control applications. Window communications mode minimizes power consumption PIDPlus is a standard feature of DeltaV and works with standard WirelessHART devices. Standard DeltaV Tools support Simulation and Tuning. The performance of PIDPlus in …
Apr
16
The Separations Research Program was established at the J.J. Pickle Research Campus in 1984. This cooperative industry/university program performs fundamental research of interest to chemical, biotechnological, petroleum refining, gas processing, pharmaceutical, and food companies. CO2 removal from stack gas is a focus project for which WirelessHART transmitters were installed for pressure and steam flow control …
Apr
09
Broadley James manufactures bioreactors and control systems (based on DeltaV) that are used in the life science industry. To explore the use of WirelessHART transmitters in bioreactor control, a portable Hyclone 100 liter disposable bioreactor was instrument with a Rosemount WirelessHART gateway and transmitters for measurement and control of pH and temperature. A WirelessHART transmitter …
Apr
02
The reliability of WirelessHART device communication has been well established. Even so, in the event of loss communication, the expected control behavior is of interest. The simulation environment was used to compare the behavior of the PIDPlus for loss of communications to a PID with a wired transmitter where the measurement value is frozen for …
Mar
26
When the PIDPlus is used with a wireless transmitter in a control application the performance will be comparable to that achieved using a wired transmitter with a wired transmitter. To demonstrate this, the module shown below was created in DeltaV that allows the control using PIDPlus using s wireless communication to be compared to the …
Mar
19
In Solution Part 1 we examined that can be made in the PID reset to accommodate slow and/or non-periodic measurement update. To further enhance the response for continuous changes in setpoint the implementation of the PIDPlus may be modified as shown below. This PIDPlus implementation is standard in DeltaV v12 and allows the reset calculation …
Mar
12
As mentioned my previous block, the communication capability of WirelessHART devices and a modification in the way the PID enable control using wireless devices. The standard communication techniques that are supported by a WirelessHART device are defined in HART 7 specification that has been adopted as an international standard, IEC 62591Ed. 1.0. The device may …
