1. Standards Certification Education & Training Publishing Conferences & Exhibits Process Control & Safety Symposium 2015 9-12 November Houston, Texas USA Industrial Advances in Wireless Control

2. Process Control & Safety Symposium 2015 9-12 November Houston, Texas USA Presenter Terry Blevins – lead the development of DeltaV advanced control products. He coauthored the ISA bestselling books Wireless Control Foundation, Advanced Control Foundation and Control Loop Foundation. Terry received a Master of Science in Electrical Engineering from Purdue University. He is a member of Control Magazine’s Process Automation Hall of Fame and an ISA Fellow. Terry is a principal technologist at Emerson Process Management. 2

3. Process Control & Safety Symposium 2015 9-12 November Houston, Texas USA Agenda Introduction Impact of Wireless Technology Continuous Control Using Wireless Transmitters Wireless Discrete Control Example installations, Test Results Wireless Throttling Valve Control Test Results Conclusions

4. Process Control & Safety Symposium 2015 9-12 November Houston, Texas USA Wireless Technology in the Process Industry Since 2009 the yearly sales of wireless field devices in the process industry (utilizing IEEE 802.15.4 radio technology) has grown from $0 to over $300,000,000. The vast majority (over 95%) of these field devices are based on the IEC 62591 WirelessHART international standard.

5. Process Control & Safety Symposium 2015 9-12 November Houston, Texas USA Evolution of HART The HART protocol has evolved from a 4–20mA based protocol to the current wired and wireless-based technology. Includes extensive features supporting security, unsolicited communication of field device parameters and advanced diagnostics. Diagnostics now include information about the device and the equipment that is being monitored.

6. Process Control & Safety Symposium 2015 9-12 November Houston, Texas USA Installation of Wireless Devices and Gateway The path of an RF signal from a device to the gateway could be upto 750 feet (230m). Heavy Obstruction – 100 ft. (30 m) Medium Obstruction – 250 ft (76 m). Light Obstruction – 500 ft (152 m). Clear Line of Site – 750 ft (228 m). The antenna for the device is mounted above obstructions and the angle of the terrain change is less than 5 degrees.

7. Process Control & Safety Symposium 2015 9-12 November Houston, Texas USA Wireless Communication Two communication techniques best fit control applications and minimize the power consumption by the wireless device transmitting the measurement value. Continuous – The device wakes up at a configured update period, senses the measurement and then communicates the value. Window – The device wakes up at a configured update period, senses the measurement and then communicates the measurement if: –The magnitude of the difference between the new measurement value and the last communicated measurement value is greater that a specified resolution –or if the time since the last communication exceeds a refresh time Window communications is the preferred method since for the same update period less power is required. 7

8. Process Control & Safety Symposium 2015 9-12 November Houston, Texas USA Integration of Wireless Network with DCS System Wireless networks are integrated into plant automation systems through the gateway. Several protocols including Modbus, OPC, and HART-IP are often supported. Connecting the wireless network to the plant automation system may be achieved in a wide variety of ways with greatly varying levels of integration. An example of a fully integrated setup is illustrated in this figure.

9. Process Control & Safety Symposium 2015 9-12 November Houston, Texas USA Using an Adapter to Access Device Diagnostics and Measurement WirelessHART adapters have been developed that access and wirelessly communicate diagnostic information. Such adapters use power drawn from the wired transmitter current loop. An adapter can also be installed on a traditional wired transmitter for wireless access to the measurement values of devices used for monitoring or control. This approach may be especially useful when working with an existing wired transmitter or when installing new four wire transmitters that have a local source of power.

10. Process Control & Safety Symposium 2015 9-12 November Houston, Texas USA Battery Replacement The power modules used in wireless devices are designed to be periodically replaced as illustrated. The power module used in some devices is designed to be intrinsically safe, which allows field replacements without the need to remove the transmitter from the process. The lithium-thionyl chloride battery cells used by many wireless devices provide high energy density, long shelf life and a wide working temperature range.

11. Process Control & Safety Symposium 2015 9-12 November Houston, Texas USA Impact of Update Rate on Battery Life When a wireless measurement transmitter is used in a control application, it is not practical to provide the same oversampling as a multi-loop controller with a wired transmitter because it quickly depletes the battery in the wireless transmitter. A wireless transmitter that communicates a new measurement value every 8, 16, or 32 seconds typically has a battery life in the range of 5–7 years.

12. Process Control & Safety Symposium 2015 9-12 November Houston, Texas USA Measurement and Control Data Sampling Rate To achieve the best control response, the rule of thumb is that feedback control should be executed four to 10 times faster than the process response time. Most multi-loop controllers are designed to oversample the measurement by a factor of 2 to 10 to minimize delay being introduced by IO access.

13. Process Control & Safety Symposium 2015 9-12 November Houston, Texas USA PID Control – Wireless Measurement Update Four Times Faster Than the Process Response Time The impact of wireless measurement update rate on control performance can be illustrated by considering a control application Lambda controller tuning rules are applied to traditional PID control for a Lambda factor = 1. Process Gain = 1 Deadtime = 2 sec Time Constant = 6 sec

14. Process Control & Safety Symposium 2015 9-12 November Houston, Texas USA Wireless Measurement Update Rate Two Times Slower Than the Process Response Time Wireless update time exceeds the process response time, the control response to setpoint changes and disturbances becomes oscillatory. Only for applications such as temperature control and level control that are characterized by slow process dynamics is it possible to use wireless transmitter update rates that are four times faster than the process response time and still achieve 3–7 year battery life.

15. Process Control & Safety Symposium 2015 9-12 November Houston, Texas USA Structuring Control for Wireless Measurements Many of the control techniques and guidelines established during the development of single loop digital controllers in the mid-‘70s are based on providing a capability that mimics an electronic analog controller. With the introduction of battery powered wireless transmitters, such update rates are impractical. Thus it is necessary to re-examine how control should be structured for use with wireless measurements and event based processing.

16. Process Control & Safety Symposium 2015 9-12 November Houston, Texas USA Re-examining PID Controller Implementation Manufacturers of DCS have approached PID implementation in a variety of ways. Many commercial products create the reset component using a positive feedback network. In a positive feedback network the time constant of the filter in the network defines the reset time in seconds per repeat.

17. Process Control & Safety Symposium 2015 9-12 November Houston, Texas USA Example – Process Response Exactly Matches Reset Network Filter Response When the PID reset is implemented using a positive-feedback network, it is easy to see that the time constant in the filter contained in this network is a direct reflection of the process dynamic response. Take, for example, a pure lag process where the PI controller is tuned for a Lambda factor of 1. On a change in setpoint, the PI controller output changes only once because the dynamic response of the filter exactly cancels the dynamic response of the process.

18. Process Control & Safety Symposium 2015 9-12 November Houston, Texas USA PIDPlus for Wireless Control To provide the best control when a measurement is not updated on a periodic basis, the PID may be restructured to reflect the reset contribution for the expected process response since the last measurement update. This PID implementation is known as PIDPlus. PIDPlus tuning is based on the process dynamics (for example, RESET = process time constant plus deadtime). PIDPlus reset automatically compensates for variations in the measurement update rate and slow measurement update rates.

19. Process Control & Safety Symposium 2015 9-12 November Houston, Texas USA PIDPlus Implementation For those processes that require derivative action, the contribution to the PID output should be recomputed and updated on an event basis i.e.only when a new measurement is received. The derivative calculation should use the elapsed time since the last new measurement to account for the fact that a new measurement value is not available for each execution of the PID.

20. Process Control & Safety Symposium 2015 9-12 November Houston, Texas USA Control for Wireless Measurement When the PIDPlus algorithm is used with a wireless transmitter in a control application, the performance will be comparable to that achieved using a wired transmitter. Example: PIDPlus using wireless transmitter compared to a standard PI controller where the wired measurement value.

21. Process Control & Safety Symposium 2015 9-12 November Houston, Texas USA Response for Measurement Loss during a Setpoint Change The reliability of WirelessHART device communication has been well established. Even so, in the event of communication loss, the expected control behavior is of interest. The example compares loss of communication with a PIDPlus against a PID with a wired transmitter where the wired measurement is frozen for a period of time.

22. Process Control & Safety Symposium 2015 9-12 November Houston, Texas USA Response for Measurement Loss after a Process Disturbance The response observed when the measurement was lost after a process disturbance is shown As illustrated by these tests, the PIDPlus provides superior dynamic response under these lost measurement conditions. PID response is significantly worse and may not be acceptable in many process applications.

23. Process Control & Safety Symposium 2015 9-12 November Houston, Texas USA Example – Enabling PIDPlus in a Control Module In many common applications such as flow or pressure control of a liquid or gas stream, an update rate that is four times faster than the process response time cannot be achieved if there is a requirement for a 3–7 year battery life. In such cases the PIDPlus should be used to implement control using a slower update rate such as 8 or 16 seconds. When PIDPlus is available as a standard feature of the distributed control system, the PIDPlus capability is selected through an option parameter of the PID.

24. Process Control & Safety Symposium 2015 9-12 November Houston, Texas USA Single Use Bioreactor (SUB) with Wireless Instrumentation The benefits of using WirelessHART transmitters with a single use bioreactor have been demonstrated by Broadley James, a major manufacturer of bioreactors for product development and production. A skid was instrumented with a 100L SUB (Single Use Bioreactor) with WirelessHART pH, temperature and pressure transmitters The bioreactor pH and temperature were controlled over a series of batch runs using WirelessHART measurements.

25. Process Control & Safety Symposium 2015 9-12 November Houston, Texas USA Bioreactor Process A wireless pressure transmitter was used to monitor pressure within the bioreactor. The pH measurement was communicated on a 1 second window communications. The temperature was reported on a 2 second using continuous (periodic) communications.

26. Process Control & Safety Symposium 2015 9-12 November Houston, Texas USA Wireless Temperature Control Response in SUB Unit A mammalian cell culture was used for each batch run. For the purpose of comparison, wired pH and temperature measurements were also available during each batch run. This screen capture shows the setpoint response of temperature control based on the WirelessHART input.

27. Process Control & Safety Symposium 2015 9-12 November Houston, Texas USA Wireless pH Control Response in SUB Unit Similarly good performance was seen for pH control using the WirelessHART input. The response to 0.05 changes in pH setpoint is shown in this screen capture.

28. Process Control & Safety Symposium 2015 9-12 November Houston, Texas USA Stripper Column at UT, Austin During the development of the PIDPlus, the wireless control performance was verified in several field trials Stripper Column shown on the left portion of the picture was addressed in a field trial conducted at the J.J. Pickle Research Campus, University of Texas PIDPlus and WirelessHART transmitters were used to control column pressure and reboiler steam flow..

29. Process Control & Safety Symposium 2015 9-12 November Houston, Texas USA Control Using Wired vs Wireless Measurement The stripper column pressure control is shown for two periods of operation: 1.PID control of steam flow and column pressure using wired measurement transmitters. 2.PIDPlus control of steam flow and column pressure using WirelessHART measurement transmitters. The same dynamic control response was observed, as illustrated in these screen captures. For these tests, the same tuning was used for both wired and wireless control.

30. Process Control & Safety Symposium 2015 9-12 November Houston, Texas USA Field Evaluation of Wireless Control The control performance is shown for column pressure and steam flow control for PIDPlus control using WirelessHART measurement transmitters (Test 2) vs PID control using wired measurement transmitters (Test 1). Comparable control performance was achieved using WirelessHART measurements and PIDPlus vs control with wired measurements and PID. However, the number of measurement samples with a WirelessHART transmitter vs a wired transmitter was reduced by a factor of 10 for flow control and a factor of six for pressure control.

31. Process Control & Safety Symposium 2015 9-12 November Houston, Texas USA Divided Wall Column Control at University of Texas, Austin The divided wall column installed at the UT J.J. Pickle Research Center, Austin TX (shown on right) is instrumented with WirelessHART temperatures and flow transmitters and prototype wireless throttling valves. Wireless valves will be used in flow control and temperature associated with column liquid distribution and side product.

32. Process Control & Safety Symposium 2015 9-12 November Houston, Texas USA Operator May Select Wired/Wireless Control

33. Process Control & Safety Symposium 2015 9-12 November Houston, Texas USA Reflux and Distillate Flow Wireless

34. Process Control & Safety Symposium 2015 9-12 November Houston, Texas USA Wireless Control - Liquid Distribution LT 630 LC 630 FC 630B TC 6078 FFC 630 TT 6078A FC 630A TT 6077A TT 6076A TY 6078 Select Temperature FC FV 630B Ratio Setpoint TT 630S TC 630S FC TV 630S FY 630 Total Flow Demand Total – FT630A FC FV 630A FT 630A FT 630B Wireless

35. Process Control & Safety Symposium 2015 9-12 November Houston, Texas USA FC630A in Cascade Control – Wireless Measurement

36. Process Control & Safety Symposium 2015 9-12 November Houston, Texas USA FC630B in Cascade Control – Wireless Measurement

37. Process Control & Safety Symposium 2015 9-12 November Houston, Texas USA TC630S In Automatic – Wireless Measurement

38. Process Control & Safety Symposium 2015 9-12 November Houston, Texas USA Wireless Valve Control – Side Product TC 6075 TT 6073B Side Product Flow TT 6075B TT 6074B TY 6075 LT 640 LC 640 FC 640A FC FV 640A FT 640A TT 630S TC 640S FC TV 640S FFC 640 FC FV 640B FC 640B FT 640B FY 640 Wireless

39. Process Control & Safety Symposium 2015 9-12 November Houston, Texas USA TC640S in Automatic – Wireless Measurement Wireless Measurement

40. Process Control & Safety Symposium 2015 9-12 November Houston, Texas USA FC640A Module – Showing Wired/Wireless Selection Wireless/Wired Selection

41. Process Control & Safety Symposium 2015 9-12 November Houston, Texas USA FC640A Liquid Flow – Comparison of Wired vs Wireless Wired Measurement Wireless Measurement

42. Process Control & Safety Symposium 2015 9-12 November Houston, Texas USA FC640B Showing Wired vs Wireless Wired Measurement Wireless Measurement

43. Process Control & Safety Symposium 2015 9-12 November Houston, Texas USA Bottoms Level and Heat Input to Reboiler Wireless

44. Process Control & Safety Symposium 2015 9-12 November Houston, Texas USA FC602 Steam Flow – Wired vs Wireless Wired Measurement Wireless Measurement

45. Process Control & Safety Symposium 2015 9-12 November Houston, Texas USA Wireless Discrete Control A wide variety of commercially available wireless transmitters and wireless on-off valves are being used in the process industry to address discrete control applications

46. Process Control & Safety Symposium 2015 9-12 November Houston, Texas USA Recycle Tank Level Control Using Point Measurement A by-product that can be used as a feedstock within a manufacturing process can be created as the result of that process or another manufacturing process To account for any imbalance when the recycle supply and is less that the process feed requirements, the recycle tank makeup stream maybe automatically regulated A WirelessHART vibrating fork liquid level transmitter may be used to detect low level and a WirelessHART on-off valve used to regulate the makeup flow.

47. Process Control & Safety Symposium 2015 9-12 November Houston, Texas USA Control Module – Discrete Point Measurement When the discrete level control setpoint, SP_D, is set to Auto (Figure 8-2), then on detection of low level the makeup valve is opened for a period of time determined by the ON_TIME parameter and then turned off. Makeup is only needed to prevent the level from dropping below the low level sensed by the level switch. This ensures that sufficient room is maintained in the recycle tank to accommodate surges in tank level when the recycle flow exceeds the feed flow.

48. Process Control & Safety Symposium 2015 9-12 November Houston, Texas USA Example – Gas-cleaning Tower At an European chemical plant, the gas-cleaning tower plays a key role in the production of titanium dioxide As originally designed, the gas- cleaning tower contents would be manually dumped using an overflow drain when the vessel became full of water and an excessive amount of sand, removed from the gas stream, had settled to the bottom. Bi-weekly maintenance to clean the vessel provided only a minimal improvement in gas cleaning efficiency. As a result, the plant installed WirelessHART field devices to automate the vessel dump. 48

49. Process Control & Safety Symposium 2015 9-12 November Houston, Texas USA Storage Tank Temperature Control There is often a requirement that storage tanks for plant feedstock or, intermediate or final product be maintained at a temperature that is required for pumping or processing. Temperature control can be automated using a wireless temperature transmitter and a wireless on-off valve to regulate the steam used to heat the tank using a wireless temperature transmitter and wireless on-off valve.

50. Process Control & Safety Symposium 2015 9-12 November Houston, Texas USA TIC206 Module for Tank Temperature Control If the mode of the temperature control is set to Auto, the discrete output to the wireless on-off steam valve is opened when the tank temperature falls below the setpoint value. When the temperature reaches setpoint, the steam valve is turned off and remains off until the temperature drops by more than the one deviation limit. When the temperature drops below setpoint by more than the DEVIATION value below setpoint the steam valve is opened again. When the mode of TC206 is changed to Manual the operator may manually open and close the steam valve using the OUT_D parameter.

51. Process Control & Safety Symposium 2015 9-12 November Houston, Texas USA Tank Temperature Control (Cont) 51

52. Process Control & Safety Symposium 2015 9-12 November Houston, Texas USA Example - AkzoNobel At the AkzoNobel surfactants processing plant in Belgium, the fatty nitriles and amines products produced by the plant are stored in 40 tanks before they are shipped to customers. As explained by Nicolas Delfosse, Process Engineer Surface Chemistry at AkzoNobel in an article for CHEManager International, a simple closed-loop discrete heating control is used to facilitate loading the products into road tankers within specific temperature parameters. A few days before loading is scheduled, the associated tanks are heated with steam. To minimize installation cost, AkzoNobel selected WirelessHART field devices to automate the tank temperature control. 52

53. Process Control & Safety Symposium 2015 9-12 November Houston, Texas USA Control Using WirelessHART Throttling Valves Based on the broad acceptance of wireless transmitters, manufacturers have developed and introduced wireless actuators for on/off valves. These devices are being used to implement closed loop discrete control. In the future manufactures will introduce wireless throttling valves that may be used with a wireless transmitter to implement closed loop control.

54. Process Control & Safety Symposium 2015 9-12 November Houston, Texas USA PIDPlus for Control with Wireless Transmitter and Wireless Valve The PIDPlus features may be combined with the modifications for control using a wireless valve. The use of the “implied or actual response indication ” as the input to a positive feedback filter enables the reset contribution to automatically compensate for delays in the positioner response

55. Process Control & Safety Symposium 2015 9-12 November Houston, Texas USA PIDPlus Structured to Minimize Changes in Target Valve Position To minimize the power consumed by the valve positioner, calculated PID output is transmitted to the wireless valve only if the criteria determined by non-periodic control communications have been met. The PID is typically scheduled to execute much faster than the minimum period at which the target valve position may be communicated to the wireless valve.

56. Process Control & Safety Symposium 2015 9-12 November Houston, Texas USA Time To Apply Command The command sent to the valve will contain the new target value and the time that the valve is to act on the new target position. This time value will be based on the time at which the new target value was accepted plus the delay time configured by the user or set by the manufacturer.

57. Process Control & Safety Symposium 2015 9-12 November Houston, Texas USA Simulation Results Using Time to Apply In the first two tests, the control performance was evaluated using a wired transmitter and a wireless valve vs a wired transmitter and a wired valve. Identical changes in setpoint and unmeasured disturbances were introduced into both control loops during the tests. In the first test, the wireless valve communication to the valve was set to 3 seconds and the delay in the PID seeing the valve response was set to 3 seconds in the simulation of wireless communication. In the second test, the delay to the valve and the valve response were set in the simulation to 6 seconds.

58. Process Control & Safety Symposium 2015 9-12 November Houston, Texas USA PID Control Using Wired Valve and Transmitter vs Wireless Valve and Transmitter The tests were repeated using a wireless transmitter with the wireless valve. The transmitter used window communications mode where the period was 6 seconds, default report time was 12 seconds and deadband in reporting was 3%.

59. Process Control & Safety Symposium 2015 9-12 November Houston, Texas USA Flow Lab Where Wireless Control Was Tested A prototype wireless valve was tested in one of Fisher Controls’ flow labs located in Marshalltown, Iowa using a DeltaV control system and its embedded PIDPlus algorithm. In these tests, closed loop flow control was evaluated using a wired and wireless valve with both wireless and wired flow measurement.

60. Process Control & Safety Symposium 2015 9-12 November Houston, Texas USA Setpoint Change Response -Wired Transmitter and Valve

61. Process Control & Safety Symposium 2015 9-12 November Houston, Texas USA Response to Unmeasured Disturbance for Wired Transmitter and Valve

62. Process Control & Safety Symposium 2015 9-12 November Houston, Texas USA Setpoint Change, Wired Transmitter and Wireless Valve

63. Process Control & Safety Symposium 2015 9-12 November Houston, Texas USA Disturbance Response, Wired Transmitter and Wireless Valve

64. Process Control & Safety Symposium 2015 9-12 November Houston, Texas USA Setpoint Change Response, Wireless Transmitter and Wireless Valve

65. Process Control & Safety Symposium 2015 9-12 November Houston, Texas USA Disturbance Change Response, Wireless Transmitter and Wireless Valve

66. Process Control & Safety Symposium 2015 9-12 November Houston, Texas USA Summary The PIDPlus has been successfully applied in a variety in wireless control applications. The reset and rate contributions updates are triggered by detection of a new communication update Wireless Discrete valve may be used in conjunction with wireless transmitter to provide wireless discrete control. In the future wireless throttling valves will be used in closed loop control through the use of time to apply command.

67. Process Control & Safety Symposium 2015 9-12 November Houston, Texas USA Where To Get More Information T. Blevins, D. Chen, M. Nixon, W. K. Wojsznis, Wireless Control Foundation – Continuous and Discrete Applications, ISA 2014, http://www.wirelesscontrolfoundation.com/ http://www.wirelesscontrolfoundation.com/ T. Blevins, M. Nixon, W. Wojsznis, PID Control Using Wireless Measurements, 2014 American Control Conference, Portland, Oregon, June 4-6, 2014 T. Blevins, M. Nixon, M. Zielinski, Using Wireless Measurements in Control Applications, 5-7 November 2013, Nashville, Tennessee T. Blevins, New day for wireless control, Control Engineering, May, 2015 T. Blevins, K. Jensen and S. Briggs, Control Using Wireless Throttling Valves, Valve Magazine, January, 2015

68. Process Control & Safety Symposium 2015 9-12 November Houston, Texas USA Thank You Questions