1. CHEM-E7140 - Process Automation
Lecture 1: Introductory concepts of process control, introduction to control system implementation

2. Contents Introduction to process automation
Benefits of process automation
Main Functions of the Process Automation Systems
Systems Architecture
Open system
Instrumentation and Communications
Field bus

3. Introduction to process automation
Process automation system allows optimal control of the process by utilizing equipment such as measuring and actuators devices of the process automation system. Automatic information processing between these devices and information channels
The control system of the process is connected to process instrumentation through the process interface
Process interface transfers all the required information from the process to the system and the system’s control information to the process
The graphical interface provides the users, with the processed data from the process and the users’ actions to the systems, for further processing

4. Introduction to process automation
Process automation is used to optimize processes and plants economically and environmentally by utilizing information collected from a plant

5. Introduction to process automation
Stands for the production and process related gathering, transfer, processing and storage of information
Process management systems
Include all the tools and procedures, which help the personnel to operate a plant or a process in the desired way
Besides process control, parts of the production and quality control related functions are automated and integrated into a plant’s information and automation system

6. Automation hierarchy © Knowpap2004
Number of functions and degree of time citicalness increases
Information is refined and its amount decreases
Process management
Process control
Measurements and actuators
© Knowpap2004

7. Contents Introduction to process automation
Benefits of process automation
Main Functions of the Process Automation Systems
Systems Architecture
Open system
Instrumentation and Communications
Field bus

8. Benefits of process automation
Less shutdowns and breaks in the production
Raw-material and chemical savings stem from more precise control of the process, typically via lowered chemical feeds
More flexible production
The level of environmental discharges has decreased due to reduction of the excess of chemicals and, for example, due to better controlled burning processes

9. Benefits of process automation
The financial benefit of an automated process comes from more efficient operation of processes and from financial optimization

10. Benefits of process automation
improvement gained in a product’s quality with computerized control and on-line analysis

11. Benefits of process automation
A decrease in quality variance can be seen
after on-line control has been applied to the system

12. Contents Introduction Main Functions of the Process Automation Systems
Systems Architecture
Distributed Control Systems
Programmable Logic Controller-based Automation System
Open system
Instrumentation and Communications
Field bus

13. Main Functions of the Process Automation Systems

14. Main Functions of the Process Automation Systems

15. Main Functions of the Process Automation Systems
An automation systems’ function can be roughly divided into:
basic functions
The basic system’s supporting functions

16. Main Functions of the Process Automation Systems: Basic functions
Collection of measurement data
Process control
Process management
Process monitoring and supervising

17. Main Functions of the Process Automation Systems: Supporting functions are
Data collection and reporting
Self diagnostics
Configuration of application and systems maintenance
Bus interfaces (serial buses to analyzers, control logics of a single device and parallel automation systems as well as information systems)

18. Contents Introduction to process automation
Benefits of process automation
Main Functions of the Process Automation Systems
Systems Architecture
Distributed Control Systems
Programmable Logic Controller-based Automation System
Open system
Instrumentation and Communications
Field bus

19. Systems Architecture Relay, timers Basic control
Robust and fast (usually used for safety circuits)
Basic control
Yksittäisten säätöpiirien toteutus
Distributed Control System (DCS)
Extensive / demanding process control tasks
Programmable Logic Controller (PLC)
Programmable Logic Controller was created at first, to replace relay and switch-based logic systems in the retailing industry
PLCs have become more common in DCD systems due to the development of technology and increasing calculation speed of microprocessors

20. Contents Introduction to process automation
Benefits of process automation
Main Functions of the Process Automation Systems
Systems Architecture
Distributed Control Systems
Programmable Logic Controller-based Automation System
Open system
Instrumentation and Communications
Field bus

21. Distributed Control Systems
DCS systems are based on separated units, which have their own processor. Those units are usually called stations; stations are connected together by a bus.
Today, lower-level controls are carried out by a microprocessor equipped with a memory controller and advanced controls are carried out, for example, with a PC.

22. Distributed Control Systems
The most crucial stations of the DCS are:
Process station
Control room station
Application/configuration station
Different special-purpose stations
Data collection and reporting stations
Bus station
Alarm station
Networks and bus solutions

23. Distributed Control Systems

24. Distributed Control Systems: Process station
The process station is the most critical level of the automation system (works independently from other stations)
The process station runs the process interface:
Measurement data collecting and processing ( for example, scaling and alarm generating)
Controls and locks the actuators as well as takes care of group start-up and sequence control

25. Distributed Control Systems: Process station
Process stations’ functions:
Connections to motor logics and to other process and control stations

26. Distributed Control Systems: Process station
Process station where an advanced control is handled by PC
Basic control
Advanced control

27. Distributed Control Systems: Control or operation station
The control or operation station’s function is to support an operator’s work by, giving him or her, a clear general picture of the process and to provide good conditions for flawless work.
Operation station functions:
Process diagrams, measurements’ and controls’ position- specific monitors
Alarm, sequence and trend monitors
Process operations

28. Distributed Control Systems: Control or operation station
The operations terminal’s devices
Frame, Power source, (CPU), memory unit, interface cards to system bus (can be implemented also with PC)
Display and operation station

29. Distributed Control Systems: Control or operation station

30. Distributed Control Systems: Control or operation station
Information processing
Operation terminal
Display

31. Distributed Control Systems: Special-purpose stations - The interface/connecting station
The interface/connecting station has connections to different information systems and to parallel automation systems
Practical implementation often requires the application-specific programming

32. Distributed Control Systems: Special-purpose stations – Logging and reporting stations
The logging and reporting station’s task, is to collect and store information. It also performs some computing and edits data to form a printable report

33. Distributed Control Systems: Special-purpose stations – Logging and reporting stations
usually a separate computer (UNIX or MS Windows / 7)
A lot of storage and possibility for back-ups (Tape drive)
Not necessarily included in the base system (sold as an option)

34. Distributed Control Systems: Special-purpose stations – Alam station
The alarms station’s task is, to take care of storage of the alarm and event history and additionally, for example, to control the alarm printers
Information processing
Database

35. Distributed Control Systems: Special-purpose stations – Application and configuration station
Application and configuration station are used for programming, changes, maintenance and documentation of automation application

36. Distributed Control Systems: Networks and bus solutions
Typically, process automation system’s bus solutions can be divided in three layers
Field bus,
System bus
Plant bus

37. Distributed Control Systems: Networks and bus solutions
Field bus
Connects i/o-frames to process stations
500 m long, 1 Mbit/s (128kBytes/s)
System bus
Connects process, control room and specific control stations of the same department together
2 km coaxial cable (optical cable), 2 Mbit/s

38. Distributed Control Systems: Networks and bus solutions
Plant bus
Connects departments together and to plant-level workstations
Mbit/s

39. Distributed Control Systems: Networks and bus solutions

40. Contents Introduction Main Functions of the Process Automation Systems
Systems Architecture
Distributed Control Systems
Programmable Logic Controller-based Automation System
Open system
Instrumentation and Communications
Field bus

41. Programmable Logic Controllers
A PLC is a microprocessor-based technology and is capable of processing measured data according to the programmed setting and program-like rules and multiple PLCs may be present in the same process
PLC-system has its software configured for each controlled process, to meet its requirements. Configuration, in this particular case, means programming
The number of PLCs depends on the distribution level and complexity of the system

42. Programmable Logic Controllers
PLC programming languages (IEC )
Ladder Logic (LL)
Instruction List (IL)
Function Block Diagram (FBD)
Structured Text (ST)
Sequential Flow Chart (SFC)

43. Programmable Logic Controllers
Recently, PLCs have become more common due to the development of technology and increasing calculation speed of microprocessors
New functionality has been added to programmable logic controllers
PLC manufacturers have also developed PLC programming tools more efficient and accessible
More versatile control solutionst

44. Programmable Logic Controllers
A “Soft-PLC” solution is an ordinary PC, with specialized software installed on it, which performs all calculations and logical operations.
It also has an interface card so it can be connected to a plant’s instrumentation components.

45. Contents Introduction to process automation
Benefits of process automation
Main Functions of the Process Automation Systems
Systems Architecture
Open system
Instrumentation and Communications
Field bus

46. Open System
Open architecture makes it possible to build a system by combining devices of different manufactures
Customer may pick the best software or hardware supplier for different parts of its automation system
The architecture of an automation system is layered, where details of one layer are hidden from the others by using standard application protocol interfaces (API)
Systems with an open architecture have three common properties:
Portability
Joint use
Capability of integration

47. Open System

48. Contents Introduction Main Functions of the Process Automation Systems
Systems Architecture
Open system
Instrumentation and Communications
Field bus

49. Instrumentation and Communications
Measurement technology is a very important part of a plant’s automation
To keep a process constantly under control it’s important to measure the process’s state in real time when possible, in other words, to collect data from the process

50. Instrumentation and Communications
feed
measurement
Process
station
Cabling

51. Instrumentation and Communications: Collection and processing of measurement data
Basic measurements of process industry are
Temperature
Pressure
Flow
Level
Measuring of material properties
Density
Moisture pH
Conductivity

52. Instrumentation and Communications: Collection and processing of measurement data
A measurement system consists of the following parts
Sampler, measurement sensor
Measurement converter and transmitter
Cabling to an I/O card
Analog-to-digital converter and data preprocessing

53. Instrumentation and Communications: Collection and processing of measurement data
The sensor, converts the measured property to a property that can be detected.
It generates a signal, proportional to the measured value by converting, for example
temperature to voltage
flow rate to pressure difference and pressure difference to current

54. Instrumentation and Communications: Collection and processing of measurement data
Electrical magnitude is usually weak and must by strengthened with an amplifier
The transmitter converts the signal to electrical standard messages
Pneumatic standard message (20-100kPa)
Electric analog message: potential message (1-5 V DC or 2-10 V DC)
Electric analog message: current message (4-20 mA DC)
Digital message

55. IInstrumentation and Communications: Collection and processing of measurement data
Standard messages are sent to an I/O-card through cabling
Cabling is usually done in the following order
From transmitter to field box
From field box to cross-connection box
From cross-connection box to I/O card

56. Instrumentation and Communications: Collection and processing of measurement data
Prohibus DP
AC 800 CM -controller
Transmitter and
field box
Cross-connection
box
Cross-connections
I/O
(analog
measurements)
Prohibus PA

57. Instrumentation and Communications: Collection and processing of measurement data
At I/O card
The electrical signal is converted by an A/D-converter into digital form (~quantisation)
Converting resolution is usually 12 or 16 bittiä (accuracy 212 = 4096 tai 65536)
Then the signal is filtered, scaled and converted into some engineering unit

58. Instrumentation and Communications: Collection and processing of measurement data

59. Instrumentation and Communications: Collection and processing of measurement data

60. Instrumentation and Communications: Actuator controls
The signals used controlling the process have to be converted to analog form with a D/A –converter
Then the signal in the form of a current message is sent to the field equipment.
The actuators control consists of the following components:
Forming the control message format and a D / A conversion
Cabling of standard message to amplifier
Structure of an actuator device
Servomotor
Transmission
Actuator
Various auxiliary equipment, such as positioners, limit switches, position transmitters

61. Instrumentation and Communications : Actuator controls
Actuators provide control / adjustment message proportional to the mechanical motion or force
Actuators, for example.
Speed controlled pump
Control valves

62. Instrumentation and Communications : Interface to automation system
Process connection is implemented with variety of interface cards
Analog input and output cards
1-16 kanavaa, 0/4-20 mA, 0-10 V
Binary interfaces
8-48 channels, 24 V-, 48 V-, 110 V-, 220V~
Special cards, such as resistance sensor, thermometer,the interrupt input cards (5-10 ms), pulse counters
Interfaces to analyzers and, for example, to Programmable logic controllers are implemented with separate interface cardsa

63. Instrumentation and Communications : Interface to automation system
Centralized I/O interface
Distributed I/O interface

64. Contents Introduction to process automation
Benefits of process automation
Main Functions of the Process Automation Systems
Systems Architecture
Open system
Instrumentation and Communications
Field bus

65. Fieldbus Fieldbus uses a digital data transmission Makes
possible to transfer information about many process variables simultaneously
Fieldbus technology enables the transfer of multi-level diagnostic information, thus making predictive maintenance possible
Two-way communication from automation systems to field equipment makes it possible to perform maintenance operations such as confi guration and calibration tasks from a workstation
Decreased startup and operating costs during the whole lifetime of a system
Remote diagnostic properties of field equipment

66. Fieldbus
International field bus standard includes eight different standard definitions:
Foundation Fieldbus
ControlNet
Profibus
P-Net
Fieldbus Foundation High Speed Ethernet
SwiftNet
WorldFIP ja
Interbus
There are also many other standardized and manufacturer’s own solutions

67. Fieldbus
Mainly two field bus solutions are competing for market share at the moment, the German-European Profibus and the Foundation Fieldbus developed by an international organization
The basis for the Profibus technology is plant automation and programmable logics. In terms of a device bus solution there is Profibus DP, and as an instrumentation bus, Profibus PA
Instrumentation bus-technology developed by Fieldbus Foundation (FF) is named H1 and the plant bus is a higher level HSE (High Speed Ethernet) based solution.

68. Fieldbus

69. Fieldbus

70. Aalto / KM / BK / Process control – Automation system
Firewall
& Router
Engineering Workspace 2-5
Plant and Control Network (TCP/IP)
History Server or (Product management server CPM+)
Combined Aspect and Connectivity Server
Engineering Workplace 1
Plant and Control Network (TCP/IP)
Flotation Cell
Heat Exchanger
1 - tank
FF HSE
Profibus DP
FF H1
Profibus PA
ProfiNET