Hall Ticket No Question Paper Code: BPE203
INSTITUTE OF AERONAUTICAL ENGINEERING
(Autonomous)
M.Tech I Semester End Examinations (Regular) February, 2017
Regulation: IARE-R16
PROGRAMMABLE LOGIC CONTROLLERS AND THEIR APPLICATIONS
(Power Electronics and Electrical Drives)
Time: 3 Hours Max Marks: 70
Answer ONE Question from each Unit
All Questions Carry Equal Marks
All parts of the question must be answered in one place only
UNIT I
1. Describe some of the main features of programmable controller.
Describe some of the benefits on using programmable controller.
2. Illustrate a typical ASCII transmission by transmitting character Z.
Explain components of a modularized PLC.
UNIT II
3. Examine the principles of programming adopted while using Ladder Diagrams to control
programmable logic controllers.
Explain the operation of the following input devices, stating the form of the signal being sensed
and the output
i. reed switch
ii. incremental shaft encoder
iii. photoelectric transmissive switch
iv. diaphragm pressure switch
4. Briefly explain the architecture of a programmable logic controller.
Determine the memory requirements for an application with the following specifications:
70 outputs, with each output driven by logic composed of 10 contact elements
-11 timers and 3 counters, each having 8 and 5 elements, respectively
-20 instructions that include addition, subtraction and comparison, each driven by 5 contact
elements
Table given below provides information about the applications memory utilization requirements
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Instruction Words of memory required
Examine ON or OFF (contacts) 1
Output coil 1
Add/subtact/compare 1
Timer/counter 3
UNIT III
5. Draw the ladder diagram for a T flip flop CR1 which will toggle only when IN1 and IN2 are both
off.
Explain branching and convergence in sequential function chart with an example.
6. Write a sequential function chart program for traffic lamp sequence controller controlling green
and red light.
Draw the ladder rungs represented by the boolean equations
i. Q
F
ii. Q A
iii. Q D
iv. Q A.B C.D
UNIT IV
7. List the various steps in commissioning programmable logic controller based system.
Explain the specifications of IEC 1131 standard.
8. Explain in detail about documentation of a PLC system.
Explain hardware and software to implement a water level controller with pump motor control
using four switches.
UNIT V
9. Explain how ladder diagram is created from process control descriptions.
Demonstrate with an example, the hardware and software design to implement any application
of your own.
10. Explain PLC applications in detail.
Specify how rotor-resistance cutting method of starting induction motor is implemented using
programmable logic controller.
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