LO1

Question 1

Define Millivolt (mV)

Answer 1

Low-level voltage signal typically ranging from 0 to 1000 millivolts. It is commonly used to measure small changes in voltage, such as those produced by sensors in temperature or pressure measurement.

Question 2

Define Milliampere (mA)

Answer 2

current signal typically ranging from 4 to 20 milliamperes. It is widely used in process control systems to transmit sensor data and control signals due to its robustness against electrical noise.

Question 3

Volt

Answer 3

represents electrical potential difference and is often used in various applications within process control systems, such as powering sensors and transmitting control signals.

Question 4

Ohm

Answer 4

Ohm signal refers to resistance measurement and is used to monitor resistance levels in different components of a process.

Question 5

Define Pulse signals

Answer 5

intermittent electrical signals characterized by discrete on-off cycles. They are commonly used for counting, timing, and controlling events in process control systems.

Question 6

Define frequenscy signals

Answer 6

Frequency signals represent the number of cycles per unit time and are utilized for measuring rotational speeds, flow rates, and other periodic phenomena in industrial processes.

Question 7

Applications of mV singals

Answer 7

mV signals are sensitive to small changes and are commonly used in sensors for temperature, pressure, and strain measurements.

Question 8

Applications of mA signals

Answer 8

mA signals are robust against noise and are frequently employed for transmitting sensor data and control signals in process control systems.

Question 9

Applications of Volt signals

Answer 9

Volt signals are versatile and can be used for various purposes, including powering sensors, transmitting control signals, and providing reference voltages for analog circuits.

Question 10

Applications of pulse signals

Answer 10

Pulse signals are used for counting, timing, and controlling events such as valve opening/closing or motor speed control.

Question 11

Applications of frequency signals

Answer 11

Frequency signals are used to measure periodic phenomena such as rotational speed, flow rate, or vibration frequency in industrial processes.

Question 12

Analog to digital conversion

Answer 12

Involves sampling the analog signal at discrete intervals and quantizing each sample into a digital value. This conversion is crucial for processing analog signals in digital control systems, as it enables precise measurement and manipulation of signals.

Question 13

Digital to analog conversion

Answer 13

Digital-to-analog conversion converts digital signals into analog voltages or currents.
It is essential for generating analog control signals to regulate processes based on digital control algorithms.
Applications include controlling actuators, variable speed drives, and other analog devices in process control systems.

Question 14

Explain multiplexing and demultiplexing

Answer 14

Multiplexing combines multiple analog or digital signals into a single signal for efficient transmission or processing.
Demultiplexing separates the combined signal back into its original components for individual processing or analysis.
These techniques are used to handle multiple signals efficiently in systems with limited resources or bandwidth.

Question 15

How is linearization of millivolt and milliamp signals performed

Answer 15

Linearization involves applying mathematical algorithms or calibration curves to convert non-linear sensor outputs into linear measurements.
This process is necessary for accurate measurement and control of physical quantities represented by millivolt and milliamp signals.
Techniques include polynomial fitting, lookup tables, and digital signal processing algorithms.

Question 16

Differentiate between analog and digital remote communication methods

Answer 16

Analog communication transmits continuous signals representing data, while digital communication encodes data into discrete binary digits (bits).
Analog methods include voltage/current modulation techniques, while digital methods use techniques such as pulse code modulation (PCM) or digital modulation schemes.
Digital communication offers better noise immunity and signal integrity compared to analog communication.

Question 17

Explain how optical communication works in remote systems

Answer 17

Optical communication uses light signals transmitted through optical fibers or free space.
It offers high bandwidth, low latency, and immunity to electromagnetic interference.
Common examples include fiber-optic communication systems used for long-distance data transmission and optical sensors for remote monitoring.

Question 18

Discuss the principles of radio and microwave communication

Answer 18

Radio communication utilizes radio waves for wireless transmission of data over long distances.
Microwave communication uses high-frequency electromagnetic waves for point-to-point or point-to-multipoint communication, often for shorter distances.
Both methods are widely used for remote communication in industrial applications, with radio being suitable for outdoor environments and microwave for line-of-sight applications.

Question 19

Compare and contrast the various methods of remote communication

Answer 19

Analog methods such as radio are suitable for simple applications with moderate data rates and communication distances.
Digital methods offer higher data rates, better noise immunity, and greater flexibility but may require more complex infrastructure.
Optical communication provides the highest bandwidth and reliability but may be more expensive to implement and maintain in some cases.