Injustice - Developers Among Us (SciFiDevCon 2024)
SCADA
1.
2. 1. Introduction
2. Evolution
3. Realization in Industry
4. Requirement for SCADA
5. SCADA Functions
6. SCADA Operations
7. Systems using SCADA
8. Working with SCADA
9. Conclusion
3. Application of SCADA is to control and
supervision of simple technical
processes
S: supervisory
C: control
A: and
D: data
A: acquisition
Earlier PLCs use to be black boxes. You
program the PLC, download the program in it,
and it will run for years. But the problem with
this was that you really don’t know what is
happening inside the PLC. Now a days
automation system contains PLCs and SCADA
software. If you use PLC & SCADA
combination the advantages you have is you
have better monitoring and control of the
plant and also you have access to the
information the way you want.
4. If you use PLC & SCADA combination the advantages you have
is you have better monitoring and control of the plant and also
you have access to the information the way you want.
7. Requirements for SCADA Functioning
1. Software (SCADA - FIX 7)
2. The operator is logged in.
3. The system is real time system.
4. Actors:
Field Devices
Local Control Center (LCC)
Remote Telemetry Units (RTU)
Master / Central Control Terminal Unit (MTU)
Operator
Supervisor
8. SCADA Functions
A SCADA system performs four functions:
1. Data acquisition
2. Networked data communication
3. Data presentation
4. Control
These functions are performed by four kinds of SCADA components:
1. Sensors: (either digital or analogue) and control relays that directly interface
with the managed system.
2. Remote telemetry units (RTUs): These are small computerized units deployed in
the field at specific sites and locations. RTUs serve as local collection points for
gathering reports from sensors and delivering commands to control relays.
3. SCADA master units: These are larger computer consoles that serve as the
central processor for the SCADA system. Master units provide a human
interface to the system and automatically regulate the managed system in
response to sensor inputs.
4. Communications networks: that connects the SCADA master unit to the RTUs
in the field.
9. SCADA performs following operations
1. System Shut Down / Startup
2. Gather Field Information
3. Perform Local Control
4. Transfer Field Information
5. Manage Field Information
6. Perform Remote Control
7. Analyze System State
8. Schedule Task
9. Balance Load
10. Adjust Settings
11. Check Status
12. Manage Logging
10. SCADA SYSTEMS
Water Distribution
Metro Train Control
Manufacturing
Oil and Gas Industries
Waste Water Treatment Plant, etc.
16. Layer’s of SCADA
SCADA system being highly complex and distributed, it is important to understand SCADA
in Terms of Layers for simplicity as shown in Figure above. The intent, forces, advantages
for the layer Patterns are the same. However here we apply this pattern on the real physical
system.
Layer 1: It is the field Units, considering the Generation, Transmission and Distribution at
one place, we have all the process controls, I/Os, status, metering, measuring values, etc. It
also includes local control.
Layer 2: The field values, I/O – analog, digital, measuring and other commands,
operations, are taken to RTUs(Remote terminal unit), IEDs(Intelligent electronic devices,
PLCs, BCUs(Bay control unit, and other I/O cards to communicate to higher end.
Layer 3: This includes all the communication cables, protocol architecture required for
higher end communication interfaced with all field signals. It is the backbone in the
modern control centers, which has immensely reduced physical wiring, big marshalling and
increased the reliability and more improved quality signals. Today latest protocols like
IEC(international elctrotechnical commission) 61850, Modbus and other proprietary
protocols are used.
Layer 4: This includes the Control centre equipped with dynamic changing states of the
system displayed on HMI, which is powerful to read values, prompt and diagnosis system
change and with a click on HMI, to carry out operations.
Layer 5: Connection with the outside world using Internet and various new technology
related to mobile / cell phone operations.
18. Benefit & Drawback
Advantages of SCADA system include Wide area connective and
pervasive ; routable ; parallel polling ; redundancy and hot stand by ;
large addressing ranges; integration of I.T to automation and
monitoring net works ; standardization ; reduce down time ; limit the
frequency of accidents; helpful in improving & Accumulating record.
Disadvantages of SCADA Technology include IP performance over
head; web enabled SCADA hosts users to remotely monitor, control
remote sites via a web browser; security concerns.