Many WirelessHART transmitter applications require that the measurement valve be used in closed loop Control. The PIDPlus capability introduced in DeltaV v11.3 enables robust control using WirelessHART measurements. A PIDPlus enhancement in DeltaV v12.3 further improves the response for setpoint changes. Details of the PIDPlus and field results using WirelessHART transmitters and PIDPlus are presented in the workshop.

1. Addressing Control
Applications Using
WirelessHART Devices
Marty Zielinski - Director of HART and
Fieldbus Technology
Mark Nixon – Director, Research
Terry Blevins – Principal Technologist

2. Presenters
 Marty Zielinski
 Terry Blevins
 Mark Nixon

3. Introduction
The PIDPlus capability in DeltaV may be used to
implement closed loop control using WirelessHART
devices. In this workshop we address
 Wireless Impact on Control
 PIDPlus for Control Using Wireless Measurements
 Performance Comparison to Wired Transmitter
 Addressing Lost Communications
 Test results – Field Installations
The PIDPlus may be used with slow and variable
communication updates

4. Challenge – Control Using WirelessHART
 Transmitter power consumption may be minimized by reducing the
number of times the measurement value is communicated.
 Conventional PID execution synchronizes the measurement value
with control action, by over-sampling the measurement by a factor of
2-10X.
 The rule of thumb to minimize control variation is to have feedback
control executed 4X to 10X times faster than the process response
time (process time constant plus process delay).
 The conventional PID design (i.e., difference equation and z-
transform) assumes that a new measurement value is available at
each execution and that control is executed on a fixed periodic
basis.

5. Conventional Approach – Over
Sampling of Measurement
Process Output
63% of Change O
Time Constant ( )
Deadtime (TD )
Process Input
I
Control Execution
New Measurement Available

6. Conventional PID - Impact of Wireless
 The underlying assumption in traditional control design is that the
PID is executed on a periodic basis 4X-10X times over the process
response time .
 When the measurement update is variable or updated less
frequently, the calculated reset action may not be appropriate.
 If control action is only executed when a new measurement is
communicated, this could result in a delayed control response to
setpoint changes and feedforward action on measured disturbances.
Conventional PID Design

7. Emerson’s WirelessHART Solution
 Power consumption of the wireless device is reduced by
transmitting the measurement value only as often as required
to allow control action to correct for unmeasured disturbances.
 The PID may be configured to execute much faster than the
measurement value is communicated. The PIDPlus is
designed to automatically compensate for the slower
measurement update and any variation in measurement
update rates.
 Tuning of the PIDPlus is based strictly on the process
dynamics independent of the measurement update rate and is
not impacted by variations in measurement update.

8. Conventional PID - Impact of Wireless
 The underlying assumption in traditional control design is that the
PID is executed on a periodic basis 4X-10X times over the process
response time .
 When the measurement update is variable or updated less
frequently, the calculated reset action may not be appropriate.
 If control action is only executed when a new measurement is
communicated, this could result in a delayed control response to
setpoint changes and feedforward action on measured disturbances.
Conventional PID Design

9. PIDPlus for WirelessHART Communications
 To provide the best control for slow or variable measurement update
rates, the PID must be modified to reflect the reset contribution for
the expected process response since the last measurement update.
 Control execution is set faster than measurement update. This
permits immediate action on setpoint change and update in the
faceplate.
 PIDPlus is a standard feature of DeltaV v11.3 (released 2010)
PIDPlus Design in DeltaV v11.3

10. PIDPlus Reset (Integral) Calculation
The filter output used in the positive feedback network is calculated in the
following manner when a new measurement is received.
PIDPlus tuning is based on the process dynamic (e.g. RESET= process
time constant plus deadtime); PIDPlus reset automatically compensates
for slow updates and variations in the measurement update rate. No
change in GAIN is required for varying update rate.

11. PIDPlus Modification for Setpoint Change
Automatic compensation for setpoint change; measurement update
rate. No need to modify tuning as sample rate changes
No Yes
PIDPlus –DeltaV v12.3 release in 2012

12. PIDPlus Using Wireless Transmitter vs.
Conventional PID and Wired Transmitter
Lambda Tuning ʎ = 1.0
Variable communication Update Rate
Control
Setpoint PIDPlus Measurement
PID
PIDPlus
Control Output
PID
Unmeasured
Disturbance

13. CONTROL PERFORMANCE DIFFERENCE
 Communications transmissions are reduced by over 96 %
using slower communication update rates.
 The impact of slower updates and variations in
measurement updates on control performance as
measured by Integral of Absolute Error (IAE) is minimized
through the use of PIDPlus for wireless communication.
Communications/Control Number of IAE
Communications
Periodic/standard PI Controller 692 123
Update Using Wireless 25 159
communication/ PI Control

14. PIDPlus - Modified Derivative Action
No Yes

15. PID Performance for Lost Communications
 The Conventional PID provides poor dynamic
response when wireless communications are lost.
 The PIDPlus improves the dynamic response
under these conditions

16. Wireless Communication Loss –
During Setpoint Change
Setpoint PIDPlus
Control
Measurement
PID
PIDPlus
Control Output
PID
Communication Loss

17. Wireless Communication Loss –
During Process Disturbance
PIDPlus
Setpoint Control
Measurement
PID
PIDPlus
Control Output
PID
Communication Loss

18. Testing PIDPlus –Communication’s Setup
 For testing purposes, the WirelessHART communications and the
process can be dynamically simulated in a DeltaV module for PID and
PIDPlus control.
 Communication setup is defined by the “Transmission” composite block.

19. Installation at Broadley James
 Portable
Hyclone 100
liter disposable
bioreactor
 Rosemount
WirelessHART
gateway and
transmitters for
measurement
and control of
pH and
temperature.
Pressure
monitored
 BioNet is based
on the DeltaV
Control system.

20. Installation at Broadley James (Cont)
 Detail view of
Rosemount pH
WirelessHART
Transmitter.
 Battery powered –
3 to 5 year battery
life expected for
this application.

21. Broadley James Bioreactor Setup
VSD
VSD Media
37 oC VSD
Inoculums TC TT
41-7 41-7
VSD Glutamine
VSD VSD
Bicarbonate Glucose
Heater
7.0 pH
AY AC AT AT
Splitter AC
41-1 41-1 41-1 41-4s1 41-4s1
0.002 g/L pH Glucose 2.0 g/L
AC AT AT AC
41-2 41-2 41-4s2 41-4s2
DO Glutamine
2.0 g/L
AT AT AT
41-5x1 41-5x2
Bioreactor
41-6
Viable Dead Product
Cells Cells
CO2 MFC LT
41-14
AY Level
Splitter VSD
41-2
O2 MFC
Drain
Air MFC

22. Example - Automatically Identified Temperature
Dynamics Using DeltaV Insight
DeltaV Insight – Standard Since DeltaV v9.3

23. Wireless Temperature Loop Test Results

24. Wireless pH Loop Test Results

25. Elimination of Ground Noise Spikes
Requirement:
Tight pH control via 0.001 pH wireless resolution setting
Temperature compensated wireless pH controlling at 6.9 pH set point
Wired pH ground noise spike

26. Separations Research Program,
University of Texas at Austin
 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

27. WirelessHART Transmitter
 Standard WirelessHART
pressure and flow transmitters
were installed to demonstrate
and test control using
WirelessHART.
 Standard WirelessHART pH
transmitters are used to support
studies associated with CO2
removal from stack gases.
 Standard WirelessHART multi-
element temperature
transmitters are used to monitor
absorber and stripper
temperatures.

28. Steam Flow To Stripper Heater

29. Column Pressure Control

30. PC215 On-line Column Pressure Control
 The same
dynamic control
Wired Measurement response was
Used in Control observed for
SP changes
 Original plant
PID tuning
was used for
both wired
and wireless
control
GAIN=2.5
RESET=4
RATE=1
Wireless Measurement
Used in Control

31. Control Performance – Wired vs Wireless
 Comparable control
as measured by IAE
LOOP FIC202 PC215 FIC202 PC215
was achieved using
Selected Input Wired Wired Wireless Wireless WirelessHART
Measurements and
IAE 9134 145 10645 198 PIDPlus vs. control
with wired
Number of 13655 6649 1184 912 measurements and
Communication PID.
Test Time (sec) 6830 6829 5926 5925  The number of
Test 1 Test 2
measurement
samples with
WirelessHART vs
Wired transmitter was
reduced by a factor of
10X for flow control
and 6X for pressure
control – accounting
for differences in test
duration.

32. Separations Research Program,
University of Texas at Austin
 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

33. Current Product: Discrete Control
Video

34. Future Product:
4300 Series Wireless On/Off Control
Release planned for the end of 2012
Currently in 7 End User Field Trials Sites
 7 different applications
 6 industrial market segments

35. Business Results Achieved
 The PIDPlus allows WirelessHART devices to be
used for closed loop control of quality parameters
that currently may not be available in the control
system.
 The reduction in process variability achieved through
closed loop control may lead to improved process
operation e.g. reduction in product quality variation,
improved efficiency.
 Field installations have documented robust control
performance using the PIDPlus with WirelessHART
transmitters. The results were shown for control of
liquid flow, gas pressure, pH and temperature.

36. Summary
 WirelessHART measurements may be used in closed loop
control applications.
– Slower reporting 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 a wireless control network is
comparable to PID with wired inputs
– PIDPlus handles lost communications better than
conventional PID.
 PIDPlus tuning depends only upon process dynamics, not on
wireless update rate

37. Where To Get More Information
 PID Advances in Industrial Control, IFAC Conference on Advances in PID Control PID'12,
Brescia, Italy, 28-30 March 2012 http://pid12.ing.unibs.it/sp_blevins.html
 DeltaV v11 PID Enhancements for Wireless, DeltaV Whitepaper, August, 2010
http://www2.emersonprocess.com/siteadmincenter/PM%20DeltaV%20Documents/Whitepap
ers/WP_DeltaV%20PID%20Enhancements%20for%20Wireless.pdf
 WirelessHART Successfully Handles Control, Chemical Processing, January, 2011
http://www2.emersonprocess.com/siteadmincenter/PM%20Articles/WirelessHART%20Succ
essfully%20Handles%20Control.pdf
 Wireless – Overcoming Challenges of PID Control& Analyzer Applications, InTech,
July/August, 2010
http://www.isa.org/InTechTemplate.cfm?template=/ContentManagement/ContentDisplay.cfm
&ContentID=83041
 PIDPlus An Enhanced PID Control Algorithm for Wireless Automation, AS-74.3199 Wireless
Automation, Aalto University, Finland http://autsys.tkk.fi/intranet/as-0.3200/attach/S09-
19/loppuraportti.pdf
 Incorporating Wireless Devices into Single-Use Disposable Bioreactor Design, 2009
Dhirubhai Ambani Life Sciences Symposium http://www.modelingandcontrol.com/Wireless-
Devices-in-Single-Use-Bioreactors.pdf
 Improving PID Control with Unreliable Communications, ISA EXPO Technical Conference,
2006. http://www.automation.com/pdf_articles/10_improving_pid.pdf
 Similarity-based Traffic Reduction to Increase Battery Life in a Wireless Process Control
Network, ISA EXPO2005, Houston, TX www.cs.utexas.edu/~sjp/publications/isa06.doc