1. Distributed Control Systems - Agenda
Activity
Estimated Time
1. Agenda 5
2. Learning Objectives
3. Historical Background 10
4. DCS Operation 40
BREAK
5. MUX/DEMUX 20
6. Bumpless Transfer 30
7. DCS Advantages
8. Review Activity
9. Summary and Wrap-Up
10. Additional Activity 50
11. Lab Activity
Slide 1
Instrumentation 2 – Session 11

2. Session 11 - Objectives Explain the purpose of a DCS.
In general terms, describe the operation of a DCS.
Explain the function of a multiplexer/demultiplexer.
Explain advantages of a DCS over an analog control system.
Explain advantages of a DCS over an analog control system:
more precise
faster
cost
more trending operation
one location/space
Given a DCS diagram, identify the major components.
Slide 2
Instrumentation 2 – Session 11

3. History of Digital Control
Slide 3
Instrumentation 2 – Session 11

4. Distributed Control Systems
Slide 4
Instrumentation 2 – Session 11

5. Individual Node
Slide 5
Instrumentation 2 – Session 11

6. MUX/DEMUX Functioning
Slide 6
Instrumentation 2 – Session 11

7. Bumpless Transfer in a DCS
BUMPY response if Bumpless switch Is NOT made by an Operator
Response
Time
Analog Controller
Response
Time
Digital Controller
Slide 7
Instrumentation 2 – Session 11

8. DCS Advantages Precision and accuracy Speed Cost Data management
Space efficiency
Safety and Reliability
Slide 8
Instrumentation 2 – Session 11

9. True - False
True
False
The local computer for each node communicates with a host computer
Slide 9
Instrumentation 2 – Session 11

10. True - False
True
False
The local computers for each node communicate with a host computer
Slide 10
Instrumentation 2 – Session 11

11. True - False
True
False
DCS eliminates the loss of accuracy that results from A/D conversion
Slide 11
Instrumentation 2 – Session 11

12. True - False
True
False
DCS eliminates the loss of accuracy that results from A/D conversion
Slide 12
Instrumentation 2 – Session 11

13. Match From the List Greater precision in process management
Slide 13
Greater precision in process management
Less interaction needed between instrumentation techs and operator
Greater ability to handle data management
Less expense for installation and maintenance
A DCS is preferred over earlier analog based systems for all the following reasons except:
Slide 13
Instrumentation 2 – Session 11

14. Match From the List Greater precision in process management
Less interaction needed between instrumentation techs and operator
Greater ability to handle data management
Less expense for installation and maintenance
A DCS is preferred over earlier analog based systems for all the following reasons except:
Slide 14
Instrumentation 2 – Session 11

15. Match From the List demultiplexer plc smart transmitter multiplexer
Multiple signals from field instruments would be forwarded to a controller by a
Slide 15
Instrumentation 2 – Session 11

16. Match From the List demultiplexer plc smart transmitter multiplexer
Multiple signals from field instruments would be forwarded to a controller by a
Slide 16
Instrumentation 2 – Session 11

17. True - False
True
False
Bumpless transfer from manual to automatic mode requires adjusting the setpoint of the controller to the actual reading and then switching the mode.
Slide 17
Instrumentation 2 – Session 11

18. True - False
True
False
Bumpless transfer from manual to automatic mode requires adjusting the setpoint of the controller to the actual reading and then switching the mode.
Slide 18
Instrumentation 2 – Session 11