Industrial
Automation System Design: Introduction
(Assignment
Questions)
1.1 What
is industrial automation (IA)?
1.2
Differentiate between IA & mechanization
1.3 Why
manufacturing/industrial process to be automated?
1.4 Make a
list of IA system tasks
1.5 Draw
process automation system hierarchy flow chart
1.6 What
are the different process automation functions in each functional level
1.7 Draw
manufacturing automation system hierarchy structure
Introduction
to Process Plant Control & Automation
(Assignment
Questions)
2.1 Why
process to be controlled?
2.2 List
various steps in control system design
2.3 List
PV5 of stirred tank heating system?
2.4 List
temperature control strategies of stirred-tank heating system
2.5 List
controlled variables, measured variable, manipulated variables and load variables
in each of the above control strategies.
2.6 Why
methodi & 2 combined and formed method 5?
2.7 Which
is the most appropriate temperature control strategy of stirred-tank heating
system, why?
2.8 List
the elements of a feed back control loop
2.9 What
are the various control devices used for IA?
2.10 What
are the advantageous of distributed control system over it’s predecessor?
2.11 What
are the advantageous of FF field bus based distributed control system over it’s
predecessor?
Data
Acquisition (DAQ) & Control system
(Assignment
Questions)
4.1 What
are the similarities and differences of PC,PAC and PLC
4.2 Based
Temperature Control Scheme
4.3 What
are the DAQ System Components?
4.5 What
is the function of a transducer?
4.6 What
is the goal of a DAQ system?
TC
Measurement
5.1 What
are the main measurement issues with TC. How they are tackled in practical
measurements?
5.2 How to
convert voltage from a TC to equivalent temperature accurately?
5.3 How
software CJC & hardware CC are implemented?
5.4
Differentiate between software CC & hardware CC.
5.5 List
TC selection criteria to select one among the TCs, for a particular
application? What is the practical significance of each of this criteria.
5.6
Differentiate between grouded and ungrounded thermocouple from application
point of view.
5.7 In TC
signal conditioner — for software CJC, Why one end of TC is connected to +ve
potential through high resistance and other end through high resistance to
ground. Will this effect on the measurement
accuracy?
How? Why high resistance is used?
5.8 In TC
signal conditioner — for software DC, What is the type of input amp is used?
Why?
5.9 In TC
signal conditioner — for software CJC, Why a 2 pole filter is used?
5.10 What
are the different sources of temperature measurement error while measuring
using a TC?
5.11 In
industrial TC is generally installed ¡n a thermowell why? Will it effect the
response time of the sensor? How & why ?
5.12
Develop the software required to measure the temperature of steam in a boiler
using J or E type TC, SCC-TCOX signal conditioning module and M series DAQ
device. Provide visual interface to the operator. VI and
all sub
VIs (sub VIs to: Convert temp to TC voltage, Convert TC voltage to temp,
Converting thermistor reading to temp), required to be developed other than
driver for DAQ device. Test the software using simulated signal. (Additional
Exercise 5-9)
Measurement
Using RTD
6.1 List
popular temperature sensors and important characteristics. How does each of
these characteristics effect the measured variable?
6.2 Which
one is the most commonly used RTD and why?
6.3 What
is the importance of the linearity of industrial process temperature sensors.
6.4 What
are the different Pt RTD types?
6.5 Will
the response time of RTD depends on sheath CD? Why?
6.6 What
are the main measurement issues with RTD. How they are tackled in practical
measurements?
6.7 What
are the different RTD configurations & Where it is used?
6.8 What
are the advantageous of ratio-metric method of measurements?
6.9 How to
convert voltage measured across an RTD to equivalent Temperature accurately?
6.10 List
RTD selection criteria to select one among the RTDs, for a particular
application? What ¡s the practical significance of each of this criteria.
6.11 How
to choose right sensor (TC Vs RTD) for an application?
6.12 What
is the general range of RTD excitation current? What is the criteria to select
the excitation current ?
6.13
Develop the software required to measure the temperature of steam in a boiler
using lOOohm, 4wire, platinum RTD (confirm to DIN 43760), SCC-RTDO1 signal
conditioning module and M series DAQ device. Provide visual interface to the
operator. VI and all sub VIs required to be developed other than driver for DAQ
device. Test the software using simulated signal. (Additional Exercise 5-10)
Measurement
Using Bridge Circuits
7.1 What
are the challenges in measuring resistance of strain gage indirectly using a
constant current source?
7.2 Why
use bridge configuration for sensors?
7.3 What
are the most common bridge configurations for sensors?
7.4 What
are the ¡mportant points to be considered while measuring with bridge?
7.5 How to
reduce errors produced by wiring resistance for remote sensitive bridge sensor?
7.6 How to
convert voltage measured across the bridge to equivalent resistance accurately?
Strain
Gage Based Measurements -Assignment Questions
8.1 What
are the different type of strain gages and compare them?
8.2 What
are the different process variables which can be measured using strain gage and
how?
8.3 What
are the different strain gage measurement issues? What is the solution for each
one of the issues?
8.4 What
are the common bridge configurations for strain gages
8.5 How to
convert voltage measured across the bridge to temperature accurately, while
measuring the temperature with 3 wire RTD in quarter
bridge
configurationi ?
8.6
Develop the software required to measure the strain using Half —bridge type II
configuration , SCC-SGO3 signal conditioning module and M
series DAQ
device. Provide visual interface to the operator. VI and all sub VIs required
to be developed other than driver for DAQ device.
Test the
software using simulated signal. (Additional Exercise 5-11)
DAQ System
Components for a Control Loop: - Transducer
(Assignment
Questions)
9.1 List
important design characteristics of transducers ?
9.2 List
important performance characteristics of transducers?
9.3 What
are the Common online measured variables & sensors for Manufacturing ?
9.4 What
are the common online measured variables & sensors for Process control ?
9.5 What
is the most commonly used analog signal range to transmit the signal through
wire media over a distance of 10 meters?
9.6 What
are the factors to be considered to select the instrumentation signal type and
levels?
9.7 What
are the most common types of information that can be extracted from signal?
9.8 The
information to be extracted from the signal is one of the important criteria to
select DAQ system and transducer, why ? Explain
DAQ System
Components for a Control Loop: - Signal Conditioner
(Assignment
Questions)
10.1 What
are the signal processing issues for thermocouple, RTD and SG transducer ? What
is the practical solution for each issue.
10.2 What
are the different analog signal conditioning functions? What is the
significance of each function? How does it effect on the measurement accuracy?
10.3 Why
DAQ device should have an INA at the input, if there is connecting wire from
sensor to DAQ device
10.4
Analog filter is provided in a DAQ device before ADC, Why?
10.5 What
is the advantage of using higher order analog filter in TC signal conditioning
module?
10.6 Can
we replace this analog filter used before digitization by a digital filter
after digitization, If can’t why ?
10.7 What
is the relation between analog filter and sampling rate, Why?
10.8 Why
analog input channels are multiplexed?
10.9 What
is isolation?
10.10 Why
and when transducer signal to be isolated?
10.11 A
110 V dc motor current, powered from a grounded (-ve terminal) dc source is
measured using a shunt and signal amplifier for controlling the motor. Examine
following possibilities
o IN-Amp
with shunt at +ve terminal of battery
o IN-Amp
with shunt at - ve terminal of battery
o IS-Amp
with shunt at - ve terminal of battery
10.12 Out of the above three methods which is the
most appropriate? Why?
10.13 Out
of the above three methods which one breaks ground loop?
10.14 How
isolation amplifier is superior to IN-Amp?
10.15 When
simultaneous sampling is required ?
10.16 How to avoid inaccuracy due to the drift in
excitation source?
10,17 What
are the signal condition functions required for each of the
following
sensors
o
Thermocouple
oRTD
o Strain
gauges
o DC Shunt
o AC
current transformer
10.18
Identify signal conditioning functions which can be implemented
using
hardware, software and both?
10.19 What
is the most commonly used of 4-20 mA transmitter type. How
they get
more immunity to the noise?
Solution (Click Here)
Analog In
put Amplifiers & Configurations
(Assignment
Questions)
11.1 Give
examples of floating signal source and ground referenced signal source?
11.2 What
are the issues with floating signal source and ground referenced signal source
for accurate signal measurement using DAQ system?
11.3
Compare following configuration for accurate signal measurement with and
without connecting wire length between source & load (both are grounded,
any one is grounded, both are ungrounded)?
o OPAMP
inverting Vs INAMP, differential configuration
o OPAMP
non inverting Vs INAMP, differential configuration
o OPAMP
differential Vs INAMP, differential configuration
11.4 Why
DAQ device should have an INA at the input, if there is connecting wire from
sensor to DAQ device
11.5 What
quality of an INAMP makes it superior than an OPAMP to use as an input device
of a DAQ system? How this quality is useful in DAQ system.
11.6
Differentiate between Difference Amplifiers Circuit realized with an OPAMP and
an INAMP?
11.7 Draw
the Classic 3-OPAmp IN-Amp Circuit, explain why gain is provided in input
section rather than output section?
11.8 For
IN-Amp why maximum I/P voltage and gain product is restricted?
11.9
Define CMMR & CMR of an amplifier. How much is the common mode signal gain
of input section of IN-Amp? How it is obtained?
11.10 Why
CMR of IN-Amp improves with increase in gain?
11.11 Why
two different capacitors are provided directly at power supply pin of PGIA? How
do they function?
11.12
Explain how noise rejection is obtained in the circuit which balanced signal
source is connected to balanced Amp with balanced wire.
Solution (Click Here)
Connecting
Analog Input Signals
(Assignment
Questions)
12.1 Why
IN-Amp is preferred for signal measurement from bridge?
12.2 How
much is the common mode voltage (CMV) in bridge circuit?
12.3 What
are the common technologies of isolation used in isolation amplifier?
12.4
Explain how isolation amplifiers are useful to reject noise?
12.5 Where
are isolation amplifier used?
Solution (Click Here)
Analog
Input Fundamentals
(Assignment
Questions)
13.1 Draw
analog input circuit block diagram of PCI-6221 device and explain the function
of each block?
13.2 Why different analog I/P ranges are provided
instead of single maximum I/P range for PCI-6221 device?
13.3 By
changing I/P range in software, What are the changes occurred in hardware
settings?
13.4
Explain the purpose of analog input low pass filter in NI 6221.Will it filter
line cycle noise from input signal?
13.5
Differentiate between filter used in TC signal conditioning module (SCC-TCOX)
& AI circuit of NI 6221? (filter used before sampling & after sampling)
13.6 Draw
the input equivalent circuit from source to PGIA of NI 6221, and explain how
channel switching affect the accuracy?
13.7 Draw
the input equivalent circuit from source to PGIA of NI 6221, and explain how
channel switching affect the accuracy?
13.8 In multi-channel scanning, what are the aspects to be considered to ensure
fast settling time?
13.9 In
multi-channel scanning, what is the problem with high impedance source?
13.10 In
multi-channel scanning, what is the importance of inter connecting cable from
source to analog input device?
13.11 In
multi-channel scanning, what are the rules to be followed in selecting channel
scanning order?
13.12 In
multi-channel scanning, why to avoid scanning faster than necessary?
13.13 What
are the different analog input data acquisition methods? Differentiate between
them?
13.14
Differentiate between buffered and non- buffered data acquisition?
13.15 Draw
AI programming flow charts and differentiate between them?
Connecting
Analog Input Signals
(Assignment
Questions)
14.1 What
are the different Ground-Reference Settings, While making these setting in
software, What are the changes occurred in hardware settings?
14.2 How
differential connection for floating signal source differ from that of
ground-referenced signal source if the load is grounded?
14.3 How
differential connection for floating signal source differ from that of
ground-referenced signal source if the load is ungrounded?
14.4 Will
differential connection for ground-referenced signal source work satisfactorily
for floating signal source, Why?
14.5 What
are the merits and demerits of fully balanced differential configuration of
floating DC sources to floating load?
14.6 Does
the same configuration of floating DC sources having low source Z (< 100
ohm) can be used for DC sources having high source Z also? Why?
14.7 Does
the same configuration of floating DC sources having low source Z (< 100
ohm) can be used for AC coupled sources also? Why?
14.8 Why
RSE confìguration is not preferred for ground-referenced signal source?
14.9 How
differential, RSE and NRSE differ one another in amplifier connection?
14.10 What
are the advantageous and disadvantageous of differential, RSE and NRSE
connections?
14.11 When
it is essential to use differential configuration?
