Survey of Industrial Control

1
Survey of Industrial Control

• Robert Nolan
• CIS 888.11E Wi01
• February 21, 200

2
Applications

• Pharmaceutical
• Chemical
• Manufacturing

3
Major Companies

• Allen-Bradley
• ABB Automation
• Foxboro
• Honeywell
• National Instruments
• Siemens

4
Types of Industrial Systems

• Distributed Control Systems (DCS)
• Process Logic Controller (PLC)
• Hybrid Control

5
Basic DCS Functions

• Control loops
• Execute special programmed logic
• Monitor inputs
• Alarm the plant operations
• Trend, log, and report data

6
DCS Architecture

• User Interface
• Plant-Wide Data Highway
• Communication Modules
• Controller Modules
• Local I/O Bus
• I/O Modules
• Process Instruments

7
Process Instruments

• Measurement
• Temperature transmitters
• Flow-meters
• pH Sensors
• Control
• Valves
• Heating elements

8
I/O Modules

• Main interface between DCS and process
• Convert information to digital form
• Signal filtering

9
Local I/O Bus

• Bridge between I/O Module and Controller Modules
• Communication
• Polling
• Serial communication

10
Local I/O Bus standards

• CANopen
• ControlNet
• DeviceNet
• EtherNet
• Fieldbus
• Interbus

• Profibus
• Smart Distrib. Sys.

11
Ethernet

• Advantages
• De facto standard
• Readily available
• Low cost

• Concerns
• Nondeterministic
• Lack of Industrial grade

12
Foundation Fieldbus

• User Layer
• Communication Stack
• Fieldbus Message Specification
• Fieldbus Access Sublayer
• Data link layer
• Physical layer

13
Foundation Fieldbus (cont.)

• Communications Stack
• Token-passing protocol
• Link-active scheduler
• Acts as central arbiter
• Executes a schedule that allows deterministic
  control and comm.
• Distributes time so all devices share the same
  sense of time

14
Foundation Fieldbus (cont.)

• User Layer
• Resource Block
• Function Blocks
• Transducer Blocks

15
CAN

• CAN frames
• Producer/Consumer network
• Multicast
• Non-destructive bitwise arbitration
• Cost-effective

16
DeviceNet

• Built on the CAN protocol
• Developed by Allen-Bradley
• Hot insertion

17
Controller Modules

• Receives the data
• Performs process calculations
• Sends actuator signals

18
Controller Module Functions

• I/O signal characterization
• Signal filtering
• Alarming I/O modules
• Ranging and engineering units

• Control logic
• Control interlocks
• Sequencing
• Batch control
• Passing on trends
• Passing on report information

19
Communication Modules

• Links
• Data highway to controller modules
• Data highway to user interfaces

20
Real-Time Data Highway

• Issues
• Synchronization
• Deterministic
• Token-passing vs. report by exception
• Variation in protocol types
• Peer-to-peer vs. collision detection
• Size and speed

21
User Interface

• Device to integrate displays and controls for
  operators

22
Honeywells PlantScape

• Hybrid Control
• Distributed Server Architecture

23
PlantScape (cont.)

• ControlNet process control network
• Ethernet Supervisory network
• Fieldbus integration module

24
Allen-Bradley--ProcessLogix
25
ProcessLogix

• ControlNet network
• Multicast capabilities

26
References

• Fundamentals of Industrial Control, Albert
  Coggan, ed., Instrument Society of America,
  1992.
• http//www.iac.honeywell.com/plantscape/
• http//www.ab.com/process/processlogix/networking.
  html
• http//www.ni.com/networks/