Roll No. …………………..
Lingaya’s University
B .T ech 3 r d Year (T er m – I X )
E n d T erm E xa mi n ati on May - Ju n e 2012
Prog ra mmab l e L og i c Con trol l ers & S CADA
(E E – 401 )
[Time: 3 Hours]
[Max. Marks: 100]
Before answering the question, candidate should ensure that they
have been supplied the correct and complete question paper. No
complaint in this regard, will be entertained after examination.
Note: – Attempt five questions in all. All questions carry equal
marks. Question no. 1 (Section A) is compulsory. Select four
questions from Section B.
Section – A
Q-1. Part – A
Select the correct answer of the following multiple
choice questions:
[10×1=10]
(i)
(ii)
Which of the following is/are component of a typical
PLC?
(a) CPU
(b) Memory module
(c) Power supply
(d) All of these
Which of the following is not a programming device of a
PLC?
(a) Hand-held device
(b) Printer
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(c) Dedicated desktop programmer
(d) Computer programmer
(iii) Which of following is a type of volatile memory?
(a) PROM
(b) EPROM
(c) EEPROM
(d) RAM
(iv) Input image table is a part of
(v)
(a) User memory
(b) Storage memory
(c) Output image table
(d) None of these
In PLC architecture, internal utility relays (dummy relays)
are
(a) Physically exist
(b) Software simulated
(c) Do not exist
(d) None of these
(vi) In ladder diagram, devices or components are generally
shown in their
(a) Excited condition
(b) Normal condition
(c) Energized condition
(d) None of these
(vii) In ladder diagram, devices, that perform a STOP function,
are generally wired in
(a) Parallel
(b) Series
(c) Both (a) and (b)
(d) None of these
(viii) If a ladder logic program is improperly written then the
program execution time will be:
(a) More
(b) Less
(c) Not affected
(d) None of these
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(ix) Which of the following is not a type of program control
instruction a typical PLC (Allen-Bradley SLC-500)?
(x)
(a) JMP
(b) LBL
(c) DAA
(d) RET
Which of the following is not a component of SCADA?
(a) Remote Technical Unit (RTU)
(b) Master station and HMI computer(s)
(c) Memory Distribution module
(d) Communication infrastructure
Q-1. Part – B
(i)
Define analog and discrete I/O modules with examples.
[5]
(ii)
Briefly describe Pneumatic and cascading timers.
[5]
Section – B
Q-2. (a)
Draw a neat diagram of a typical PLC and explain its
different components.
[10]
(b)
Explain fixed I/O section and modular I/O sections. How
fixed I/O section is different from modular I/O sections?
[10]
Q-3. (a)
Explain memory organization of a PLC. Give the
configuration of the storage memory of a typical PLC.
[10]
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(b)
Explain guarding against electrostatic discharge (ESD)
and precautions taken to reduce the possible damage from
it.
[10]
Q-4. (a)
What is a programming device? Explain different types of
programming devices.
[10]
(b) Discuss advantages and disadvantages of different
programming devices.
[10]
Q-5. (a)
Explain the working of a basic stop/start circuit of a
typical PLC.
[10]
(b)
Define wiring diagram and ladder diagram. Briefly
describe different ladder diagram rules.
[10]
Q-6. (a)
Define and describe the importance of program control
instruction in PLC programming.
[10]
(b)
What do you mean by master control relay instruction?
Explain with an example.
[10]
Q-7. (a)
Explain the SCADA system with a neat block diagram.
[10]
(b)
What is automatic SCADA? Describe the hierarchical of
SCADA?
[10]
Q-8.
Write short notes on any Two of the following-(i) Network limitation of a PLC
(ii) Processor scan
(iii) Remote Technical Unit (RTU)
[20]
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