III

Module 3

3 Data transmission and Virtual instrumenta-

tion system .......................................................... 87
3.1 Cable transmission of analog and digital data . 87
3.2 Fiber optic data transmission...................................... 88
3.3 Pneumatic Transmission ......................................................89
3.4 Process control network ................................................91
3.5 Functions and General characteristics of a process
control network ............................................................... 92
3.6 Fieldbus and Profibus..................................................... 92
3.7 Radio Communication ...............................................92
3.8 Wireless communication .............................................. 93
3.9 Wireless Local Area Network (WLAN) ...................... 95
3.10 Virtual instrumentation system ........................................97
3.11 Concept of Graphical programming .................. 100
3.12 Important Questions .......................................................... 100
 3. Data transmission and Virtual
instrumentation system

Syllabus
Cable transmission of analog and digital data, Fiber optic data transmission, Pneumatic transmission.
Process control Network- Functions- General characteristics- Fieldbus and Profibus, radio-wireless
communication, WLAN architecture. Virtual instrumentation system: The architecture of virtual
instruments – Virtual instruments and traditional instruments – concepts of graphical programming

3.1 Cable transmission of analog and digital data

Cable transmission of analog and digital data refers to the use of cables to transmit information
in the form of analog or digital signals. This type of transmission is used in various applications,
including telecommunications, broadcasting, and networking.

Analog Transmission
Analog transmission is a method of transmitting data in the form of analog signals. This involves
the use of cables to transmit information through electrical signals, which vary continuously over
time. Analog signals can be used to transmit voice and video signals, and they are commonly used
in applications such as cable TV and radio broadcasting.

Digital Transmission
Digital transmission is a method of transmitting data in the form of digital signals. This involves
the use of cables to transmit information through a series of discrete digital signals, represented as
0s and 1s. Digital signals can be used to transmit various types of data, including text, images, and
audio, and they are commonly used in applications such as the Internet and computer networks.

Cable Transmission
Cable transmission of analog and digital data can be achieved using various types of cables,
including coaxial cables, twisted pair cables, and fiber optic cables. Coaxial cables are commonly
used for cable TV and broadband Internet, while twisted pair cables are used for telephone lines
and local area networks (LANs). Fiber optic cables are used for long-distance data transmission,
such as in telecommunications and the Internet.
3.1.1 Advantages of Cable Transmission
Cable transmission of analog and digital data offers several advantages, including high data transfer
rates, low interference, and high reliability. Cable transmission also allows for long-distance data
transmission without the need for signal boosters or repeaters, which can be expensive and introduce
additional noise and distortion to the signal.

3.1.2 Disadvantages of Cable Transmission

Cable transmission of analog and digital data also has some disadvantages, including high installa-
tion costs, vulnerability to physical damage, and limited bandwidth capacity. Additionally, different
types of cables have different limitations, such as the maximum distance over which they can
transmit data and the type of signal they can support.

3.2 Fiber optic data transmission

Fiber optic data transmission is a method of sending information over long distances using light
signals that travel through optical fibers.An optical Fiber is a thin, flexible, transparent Fiber that
acts as a waveguide, or "light pipe", to transmit light between the two ends of the Fiber.Optical
fibers are widely used in Fiber-optic communications, which permits transmission over longer
distances and at higher bandwidths (data rates) than other forms of communication.Fibers are used
instead of metal wires because signals travel along them with less loss and are also immune to
electromagnetic interference. Here are some key notes on fiber optic data transmission:
1. The basic principle of fiber optic data transmission is that light is used to carry information
through a thin glass or plastic fiber. This is done by transmitting pulses of light down the
fiber, which are then received and converted back into electrical signals at the other end.
2. Fiber optic cables consist of one or more strands of optical fibers that are surrounded by
protective coatings. These coatings are designed to protect the fragile fibers from damage
and to ensure that the light signals remain focused and travel in the correct direction.
3. Fiber optic data transmission offers several advantages over traditional copper wiring, includ-
ing greater bandwidth, faster data transfer speeds, and longer transmission distances. This
makes it ideal for applications such as high-speed internet, video streaming, and long-distance
telecommunications.
4. There are two types of fiber optic cables: single-mode and multimode. Single-mode fibers
have a small core diameter and are designed for long-distance transmission, while multimode
fibers have a larger core diameter and are better suited for shorter distances.
5. Fiber optic data transmission is immune to electromagnetic interference, which can cause
problems for copper wiring. It is also less susceptible to signal loss over long distances,
which can degrade the quality of the signal and slow down data transfer speeds.
6. Fiber optic data transmission is commonly used in telecommunications networks, including
long-distance telephone, cable television, and internet infrastructure. It is also used in other
applications such as medical imaging, military communication, and industrial automation.
7. The installation and maintenance of fiber optic data transmission systems can be more com-
plex and expensive than traditional copper wiring, but the benefits of the technology make it
a popular choice for many applications.

Overall, fiber optic data transmission is a powerful and reliable technology that offers many
advantages over traditional copper wiring. As the demand for high-speed, long-distance data
transmission continues to grow, fiber optic technology is likely to play an increasingly important
role in our lives.
 Figure 3.1: Block diagram of OFC system

3.2.1 Element of an Optical Fiber Transmission link

Basic block diagram of optical fiber communication system consists of following important blocks
1. Transmitter
2. Information channel
3. Receiver.
• The light beam pulses are then fed into a fiber– optic cable where they are transmitted over
long distances.
• At the receiving end, a light sensitive device known as a photocell or light detector is used to
detect the light pulses.
• This photocell or photo detector converts the light pulses into an electrical signal.
• The electrical pulses are amplified and reshaped back into digital form.

3.3 Pneumatic Transmission

Pneumatic transmission is transfer power by gas pressure or information fluid by compressed gas
as the working medium.
The system of transfer power is to transfer the compressed gas through the pipe and control
valve to the pneumatic actuator, which can transform the pressure of the compressed gas into the
work of mechanical energy.
The system of transmitting information is to use the pneumatic logic element or the jet element
to realize the function of logic operation, also called pneumatic control system.

3.3.1 Characteristics of pneumatic transmission

Low working pressure, the average of 0.3 - 0800000 mpa, gas viscosity is small, a small loss in
pipelines is advantageous for the gas supply and middle distance transportation, the use is safe, no
explosion and shock hazard, with overload protection ability; but the air pressure is low and needs
an air supply.
 Figure 3.2: Pneumatic transmission

3.3.2 Composition of pneumatic transmission

• Pneumatic transmission consists of air source, pneumatic actuator, pneumatic control valve
and pneumatic auxiliary.
• Air sources are generally supplied by compressors.
• The pneumatic actuator converts the pressure of the compressed gas into mechanical energy
used to drive the working parts, including the cylinder and the pneumatic motor.
• The pneumatic control valve is used to adjust the direction, pressure and flow of the air,
which is correspondingly divided into directional control valve, pressure control valve and
flow control valve.
• Pneumatic accessories include: air purifier, Air lubricator, noise mufflers, pipe joints, etc.
• There are also aerodynamic sensors that are used to sensor and transmit information in a
pneumatic transmission.

3.3.3 Advantages of pneumatic transmission

1. Use air as the medium, inexhaustible, source is convenient, direct discharge after use, do
not pollute the environment, do not need to go back to the windpipe so the pipeline is not
complicated;
2. Small air viscosity, small flow energy dissipation, suitable for centralized gas supply and
long-distance transportation;
3. Safe and reliable, do not need fire and explosion protection, can work in an environment such
as high temperature, radiation, humidity, dust and so on;
4. The pneumatic transmission is quick;
5. The structure of pneumatic components is simple, easy to process, long service life, easy
to maintain, the pipeline is not easy to clog, and the medium does not have the problem of
metamorphic replacement.

3.3.4 Disadvantages of pneumatic transmission

1. Air compressibility is large, so the dynamic stability of the pneumatic system is poor, and the
impact of load change on working speed is great.
2. Low pressure of the pneumatic system, not easy to make large output and torque;
3. Air control signal transmission is slower than the electron and the speed of light, not suitable
for high-speed and complex transmission system;
4. Large exhaust noise;

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3.4 Process control network
A process control network (PCN) is a specialized type of computer network used in industrial
process control and automation. It is designed to support the operation of critical infrastructure,
such as chemical plants, oil refineries, and power stations.
• Process control networks are used to monitor and control industrial processes, such as
the production of chemicals or the generation of electricity. They typically consist of a
combination of hardware and software components, including sensors, programmable logic
controllers (PLCs), human-machine interfaces (HMIs), and other specialized devices.
• The primary goal of a process control network is to ensure the safe and efficient operation
of critical infrastructure. This requires strict control over the flow of data and the access to
control systems, in order to prevent unauthorized access or malicious attacks.
• Process control networks are typically isolated from other types of computer networks, such
as corporate IT networks or the Internet. This isolation helps to prevent external threats from
compromising the integrity of the network.
• Due to the critical nature of the systems being controlled by a process control network,
reliability and availability are key design considerations. This includes redundancy in
hardware and communications pathways, as well as the use of fault-tolerant architectures.
• Despite their isolation from other networks, process control networks can still be vulnerable
to cyber attacks. Malicious actors can exploit vulnerabilities in software, hardware, or
communications protocols to gain unauthorized access to control systems, potentially causing
physical damage or disrupting operations.
• To mitigate these risks, process control networks often incorporate a range of security
measures, such as firewalls, intrusion detection systems, and access controls. Regular
security audits and testing are also important to ensure that the network remains secure over
time.
• As the demand for automation and digitalization in industrial processes grows, process
control networks are likely to become increasingly complex and interconnected. This will
require ongoing efforts to balance the benefits of automation with the need for security and
resilience in critical infrastructure.
• So a process control network is a specialized computer network used to monitor and control
industrial processes. Due to the critical nature of these systems, security and reliability are
key considerations in the design and operation of these networks. Ongoing efforts to balance
automation and digitalization with security and resilience will be essential as these networks
continue to evolve.
PCN networks more or less consist of the following components:
1. Human-Machine Interface (HMI): The Human-Machine Interface (HMI) is a device which
shows data to the human operator for monitoring and controlling remotely installed systems.
Examples include command-line interfaces, web-based interfaces, touchscreen interfaces and
Graphical User Interface (GUI)
2. Programmable Logic Controller (PLC): The Programmable Logic Controller (PLC) is a kind
of controller for various processes like water flow and water level, speed, status of valve,
temperature and so on. A PLC has a set of inputs for various processes and accordingly
produces outputs for controlling them
3. Remote Terminal Unit (RTU): The Remote Terminal Unit (RTU) is a system which is
connected to various sensors involved in the process. It converts sensor data to digital form
and sends it to SCADA systems
4. Master Terminal Units (MTU): Master Terminal Units (MTUs) is the master of the PCN
network. What the CPU is to the computer, MTU is to the PCN. They are central monitoring
and control stations which control multiple RTUs placed at remote locations
3.5 Functions and General characteristics of a process control
network
1. Monitoring and control: The primary function of a PCN is to monitor and control industrial
processes in real-time. This involves collecting data from sensors and other devices, analyzing
the data, and sending commands to control systems to adjust the process as needed.
2. Data storage and analysis: PCNs also store data about the industrial processes they monitor,
which can be used for analysis and optimization. This includes historical data that can be
used for trend analysis and predictive maintenance, as well as real-time data that can be used
for process control.
3. Communication: PCNs rely on communication protocols to facilitate the exchange of data
between devices on the network. These protocols must be reliable and secure, and they may
need to support real-time communication for time-critical applications.
4. Redundancy: To ensure reliable operation, PCNs typically incorporate redundant hardware
and communications pathways. This helps to ensure that the network can continue to operate
even if one component fails.
5. Security: As mentioned earlier, security is a critical function of a PCN. This includes
measures to prevent unauthorized access, detect and respond to security incidents, and ensure
the integrity and availability of the network.
6. Maintenance and troubleshooting: PCNs require ongoing maintenance and troubleshooting to
ensure that they continue to operate effectively. This may involve software updates, hardware
upgrades, or diagnostic testing

3.6 Fieldbus and Profibus

• Fieldbus and PROFIBUS are two common industrial communication protocols used in
process control networks (PCNs) to enable communication and control between devices such
as sensors, actuators, controllers, and other industrial equipment.
• Fieldbus is a generic term used to describe a family of industrial communication protocols
that use digital signaling to enable communication between devices in a PCN. Fieldbus
protocols are designed to operate over a single two-wire cable, allowing multiple devices
to share the same physical communication network. Fieldbus protocols can support a wide
range of functions, including control, data acquisition, and device diagnostics.
• PROFIBUS, on the other hand, is a specific type of Fieldbus protocol that was developed by
Siemens in the early 1990s. PROFIBUS uses a master/slave architecture to allow a controller
(the master) to communicate with multiple devices (the slaves) on the network. PROFIBUS
supports a wide range of applications, including process control, motion control, and safety
systems.
• PROFIBUS is widely used in many industrial applications, including manufacturing, process
automation, and building automation. It has been adopted as a standard by many organi-
zations, including the International Electrotechnical Commission (IEC) and the European
Committee for Electrotechnical Standardization (CENELEC).
Overall, both Fieldbus and PROFIBUS are important communication protocols in industrial au-
tomation, enabling reliable and efficient communication between devices in PCNs.

3.7 Radio Communication

In radio communication systems, information is carried across space using radio waves. At the
sending end, the information to be sent is converted by some type of transducer to a time-varying
electrical signal called the modulation signal. The modulation signal may be an audio signal
representing sound from a microphone, a video signal representing moving images from a video

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 Figure 3.3: Radio Communication

camera, or a digital signal consisting of a sequence of bits representing binary data from a computer.
The modulation signal is applied to a radio transmitter. In the transmitter, an electronic oscillator
generates an alternating current oscillating at a radio frequency, called the carrier wave because it
serves to "carry" the information through the air. The information signal is used to modulate the
carrier, varying some aspect of the carrier wave, impressing the information on the carrier. Radio
communication. Information such as sound is converted by a transducer such as a microphone to an
electrical signal, which modulates a radio wave produced by the transmitter. A receiver intercepts
the radio wave and extracts the information-bearing modulation signal, which is converted back to
a human usable form with another transducer such as a loudspeaker. Different radio systems use
different modulation methods:
1. AM (amplitude modulation) – in an AM transmitter, the amplitude (strength) of the radio
carrier wave is varied by the modulation signal;
2. FM (frequency modulation) – in an FM transmitter, the frequency of the radio carrier wave is
varied by the modulation signal;
3. FSK (frequency-shift keying) – used in wireless digital devices to transmit digital signals,
the frequency of the carrier wave is shifted between frequencies.
4. OFDM (orthogonal frequency-division multiplexing) – a family of digital modulation meth-
ods widely used in high bandwidth systems such as Wi-Fi networks, cellphones, digital
television broadcasting, and digital audio broadcasting (DAB) to transmit digital data using a
minimum of radio spectrum bandwidth. It has higher spectral efficiency and more resistance
to fading than AM or FM.

3.8 Wireless communication

Wireless communication involves the transmission of information over a distance without the help
of wires, cables or any other forms of electrical conductors.
Wireless communication is a broad term that incorporates all procedures and forms of con-
necting and communicating between two or more devices using a wireless signal through wireless
communication technologies and devices.
Wireless communication is the transfer of information between two or more points that are
not physically connected by a wired medium, such as cables or fiber optic lines. Instead, wireless
communication uses electromagnetic waves to carry the information over the air.
Some common types of wireless communication include:
1. Wi-Fi: A wireless networking technology that allows devices to connect to the internet or
other networks without the need for cables.
2. Bluetooth: A short-range wireless technology used to connect devices such as smartphones,
headphones, and speakers.
 3. Cellular communication: A wireless communication technology that allows mobile phones
to connect to cellular networks to make calls, send texts, and access the internet.
4. Satellite communication: A wireless communication technology that uses satellites orbiting
the earth to send and receive data over long distances.
Wireless communication has become increasingly important in our daily lives, as more devices
become connected to the internet and each other. However, there are also concerns around privacy,
security, and potential health effects of long-term exposure to electromagnetic waves.

3.8.1 Wireless communication Advantages

Wireless communication involves transfer of information without any physical connection be-
tween two or more points. Because of this absence of any ’physical infrastructure’, wireless
communication has certain advantages. This would often include collapsing distance or space.
Wireless communication has several advantages; the most important ones are discussed below
3.8.1.1 Cost effectiveness
Wired communication entails the use of connection wires. In wireless networks, communication
does not require elaborate physical infrastructure or maintenance practices. Hence the cost is
reduced.
Example: Any company providing wireless communication services does not incur a lot of
costs, and as a result, it is able to charge cheaply with regard to its customer fees.
3.8.1.2 Flexibility
Wireless communication enables people to communicate regardless of their location. It is not
necessary to be in an office or some telephone booth in order to pass and receive messages.
Example:Miners in the outback can rely on satellite phones to call their loved ones, and thus,
help improve their general welfare by keeping them in touch with the people who mean the most to
them.
3.8.1.3 Convenience
Wireless communication devices like mobile phones are quite simple and therefore allow anyone
to use them, wherever they may be. There is no need to physically connect anything in order to
receive or pass messages.
Example: Wireless communications services can also be seen in Internet technologies such as
Wi-Fi. With no network cables hampering movement, we can now connect with almost anyone,
anywhere, anytime.
3.8.1.4 Speed
Improvements can also be seen in speed. The network connectivity or the accessibility were much
improved in accuracy and speed.
Example: A wireless remote can operate a system faster than a wired one. The wireless control
of a machine can easily stop its working if something goes wrong, whereas direct operation can’t
act so fast.
3.8.1.5 Accessibility
The wireless technology helps easy accessibility as the remote areas where ground lines can’t be
properly laid, are being easily connected to the network.
Example:In rural regions, online education is now possible. Educators no longer need to travel
to far-flung areas to teach their lessons. Thanks to live streaming of their educational modules
3.8.1.6 Constant connectivity
Constant connectivity also ensures that people can respond to emergencies relatively quickly.

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 h!

Figure 3.4: WLAN

Example: A wireless mobile can ensure you a constant connectivity though you move from
place to place or while you travel, whereas a wired land line can’t.

3.9 Wireless Local Area Network (WLAN)

A WLAN (wireless local area network) is a network that enables devices to connect and communi-
cate wirelessly. In contrast to a standard wired LAN, where devices connect via Ethernet cables,
WLAN devices interact via Wi-Fi. While a WLAN differs from a standard LAN in appearance,
it performs the same services. DHCP is commonly used to add and set up new devices. They
can communicate with other network devices in the same manner as wired devices can. The
fundamental distinction is in the manner in which data is conveyed. In a LAN, data is sent in a
sequence of Ethernet packets through physical connections. Packets are transmitted over the air in
a WLAN.

WLANs have expanded in popularity in tandem with wireless gadgets. In fact, wireless
routers currently account for the majority of router sales. A wireless router acts as a base station,
allowing any Wi-Fi-enabled device within range of the router’s wireless signal to connect wirelessly.
Laptops, tablets, smartphones, and other wireless devices, such as smart appliances and smart home
controllers, are included in this category. Wireless routers are usually connected to a cable modem
and perhaps another Internet-connected device in order to enable Internet access to connected
devices.

3.9.1 WLAN Architecture

1. Stations: Stations are network components that communicate wirelessly. They might be
access points or endpoints, and each has its own network address
2. Basic Service Set (BSS): A BSS is a network that connects a group of stations. An Indepen-
dent BSS is a set of stations in ad hoc networks (IBSS). An Extended Service Set (ESS) is a
 Figure 3.5: BSS

Figure 3.6: WLAN

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 collection of connected BSSs, such as those found in a network with many access points.
3. Distribution system: In an ESS, the distribution system connects access points. Wired or
wireless connectivity are available. Mesh or its own WDS protocol can be used by a wireless
distribution system (WDS). Fixed wireless is a type of radio transmission used to connect
two geographically separated access points.
4. Bridge : A WLAN bridge connects a WLAN to a LAN or an access point.
5. Endpoint: An endpoint is a computer, mobile device, printer, or Internet of Things (IoT)
device used by a user.
6. Access point: The base station that serves as a connection point for other stations is known
as the access point. The term "access" refers to the stations’ network connection, but it could
also refer to internet access because many routers also function as modems. Ethernet cables
or wireless connections can be used to connect access points in an ESS.

3.10 Virtual instrumentation system

A virtual instrumentation system is a type of measurement and control system that uses software
and hardware components to acquire, process, display, and analyze data. The term "virtual" refers
to the fact that the system is implemented using a computer, rather than traditional hardware-based
systems.
In a virtual instrumentation system, the hardware components typically consist of sensors or
transducers that convert physical signals such as temperature, pressure, or voltage into electrical
signals that can be processed by the computer. These signals are then digitized using analog-to-
digital converters and processed using software to perform tasks such as filtering, analysis, and
control.
The software component of the system is typically implemented using graphical programming
environments such as LabVIEW, MATLAB, or Simulink. These environments allow users to create
virtual instruments that can be used to perform a wide range of tasks, from simple data acquisition
and analysis to complex control systems.
Virtual instrumentation systems have a number of advantages over traditional hardware-based
systems. They are often more flexible and adaptable, allowing users to easily modify and customize
their systems as needed. They can also be more cost-effective, since they can be implemented using
off-the-shelf hardware components and standard software tools. Additionally, virtual instrumenta-
tion systems can be easily integrated with other software tools and data analysis platforms, allowing
users to easily share and analyze their data.
KEY POINTS
• Virtual instrumentation is an inter disciplinary field that merges sensing, hardware and
software technologies in order to create flexible and sophisticated instruments for control
and monitoring applications
• Virtual Instrumentation is the use of customizable software and modular measurement
hardware to create user defined measurement systems called virtual instruments.
• Virtual instrument provides all the software and hardware needed to accomplish the measure-
ment or control task
• Virtual instrumentation combines mainstream commercial technologies, such as the PC, with
flexible software and a wide variety of measurement and control hardware

3.10.1 Virtual Instrument Architecture

A virtual instrument is composed of the following blocks:
• Sensor Module,
• Sensor Interface,
• Medical Information Systems Interface,
 • Processing Module,
• Database Interface, and
• User Interface
The sensor module detects physical signal and transforms it into electrical form, conditions the
signal, and transforms it into a digital form for further manipulation. Through a sensor interface, the
sensor module communicates with a computer. Once the data are in a digital form on a computer,
they can be processed, mixed, compared, and otherwise manipulated, or stored in a database. Then,
the data may be displayed, or converted back to analog form for further process control. Biomedical
virtual instruments are often integrated with some other medical information systems such as
hospital information systems. In this way the configuration settings and the data measured may be
stored and associated with patient records.
1. Sensor module
• The sensor module performs signal conditioning and transforms it into a digital form
for further manipulation.
• Once the data are in a digital form on a computer, they can be displayed, processed,
mixed, compared, stored in a database, or converted back to analog form for further
process control.
• The database can also store configuration settings and signal records.
• The sensor module interfaces a virtual instrument to the external, mostly analog world
transforming measured signals into computer readable form.
A sensor module principally consists of three main parts:
1 The sensor,
2 The signal conditioning part, and
3 The A/D converter.
According to their position, biomedical sensors can be classified as:
1. Implanted sensors, where the sensor is located inside the user’s body, for example, intracra-
nial stimulation.
2. On-the-body sensors are the most commonly used biomedical sensors. Some of those
sensors, such as EEG or ECG electrodes, require additional gel to decrease contact resistance.
3. Noncontact sensors, such as optical sensors and cameras that do not require any physical
contact with an object.
The signal-conditioning module performs (usually analog) signal conditioning prior to AD
conversion, such as . This module usually does the amplification, transducer excitation, lin-
earization, isolation, or filtering of detected signals. The A/D converter changes the detected
and conditioned voltage into a digital value
2. Sensor interface
There are many interfaces used for communication between sensors modules and the com-
puter
According to the type of connection, sensor interfaces can be classified as wired and wireless

3. Processing Module
Integration of the general purpose microprocessors/microcontrollers allowed flexible imple-
mentation of sophisticated processing functions.
• As the functionality of a virtual instrument depends very little on dedicated hardware, which
principally does not perform any complex processing, functionality and appearance of the
virtual instrument may be completely changed utilizing different processing functions.
• Broadly speaking, processing function used in virtual instrumentation may be classified as
analytic processing and artificial intelligence techniques.

Analytic processing

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 Analytic functions define clear functional relations among input parameters. Some of
the common analyses used in virtual instrumentation include spectral analysis, filtering,
windowing, transforms, peak detection, or curve
Artificial intelligence techniques
Artificial intelligence technologies could be used to enhance and improve the efficiency, the
capability, and the features of instrumentation in application areas related to measurement,
system identification, and control . These techniques exploit the advanced computational
capabilities of modern computing systems to manipulate the sampled input signals and extract
the desired measurements.Artificial intelligence technologies, such as neural networks, fuzzy
logic and expert systems, were applied in various applications, including sensor fusion to
high-level sensors, system identification, prediction, system control, complex measurement
procedures, calibration, and instrument fault detection and isolation. Various nonlinear signal
processing, including fuzzy logic and neural networks, are also common tools in analysis of
biomedical signals
4. Database interface
Computerized instrumentation allows measured data to be stored for off-line processing, or
to keep record as a part of the patient record There are several currently available database
technologies that can be used for this purpose
5. Medical information system interface
Virtual instruments are increasingly integrated with other medical information systems, such
as hospital information systems.They can be used to create executive dashboards, supporting
decision support, real time alerts and predictive warnings .

3.10.2 Compare traditional instruments and virtual instruments

Traditional instrumentation and virtual instrumentation are two different approaches to acquiring
and measuring data in various fields. Here are some of the key differences between these two types
of instrumentation:
Physical Presence: Traditional instrumentation involves the use of physical instruments, such as
gauges, sensors, and meters, which are placed at the point of measurement. Virtual instrumentation,
on the other hand, involves the use of software-based instruments that operate on data collected
from sensors or other sources.
Measurement Techniques: Traditional instrumentation typically relies on analog measurement
techniques, such as measuring voltage or current, while virtual instrumentation relies on digital
techniques, such as sampling and processing data.
Data Acquisition: Traditional instrumentation typically involves manual data collection, where
readings are taken from physical instruments and recorded manually. In contrast, virtual instrumen-
tation uses automated data acquisition systems that can collect, process, and analyze large amounts
of data in real-time.
Flexibility: Virtual instrumentation offers more flexibility and customization than traditional
instrumentation. With virtual instrumentation, the data can be displayed in different formats and
can be manipulated to extract more information than with traditional instrumentation.
Cost: Traditional instrumentation can be more expensive than virtual instrumentation due to the
cost of physical instruments, especially if the instruments are rare or specialized. Virtual instrumen-
tation can be much cheaper and accessible, since it requires only software-based instruments and
standard computer hardware.
Learning Curve: Traditional instrumentation requires a certain level of expertise to set up and
operate, while virtual instrumentation can be set up and configured easily by individuals with
limited technical knowledge.
 Figure 3.7: Comparison

3.11 Concept of Graphical programming

• Graphical programming is a visually-oriented approach to programming.
• Graphical programming is easier and more intuitive to use than traditional textual program-
ming.
• Textual programming requires the programmers to be reasonably proficient in the program-
ming language.
• Non-programmers can easily learn the graphical approach faster at less amount of time.
• The main advantage of textual languages like C is that they tend to have faster graphical
approach execution time and better performance than graphical programs.
• Textual programming environments are popular and many engineers are trained to use these
standardized tools.
• Graphical environments are better for nonprogrammers and useful for developing virtual
instruments quickly and need to be reconfigured rapidly.
• The most important task is to understand how to use standard analysis packages that can
directly input data from the instruments and can be used to analyze, store and present the
information in a useful format.
• Irrespective of whether it is classical or graphical environment any system with a graphical
system design can be looked at as being composed of two parts—the user interface and the
underlying code. The code in a conventional language like C comprises a number of routines
while in the graphical language G it is a collection of icons interconnected by multi-colored
lines

3.12 Important Questions

1. Compare Profibus and Fieldbus used in data transmission
2. List the advantages of virtual instrumentation systems
3. Explain the architecture of Virtual instrumentation system
4. Describe the concept of graphical programming
5. Explain the different types of communication networks used for data collection and control
in industrial applications
6. Explain Field bus
7. Explain Cable transmission of analog and digital data

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 8. Explain about Fiber optic data transmission
9. Describe Pneumatic transmission
10. Compare radio and wireless communication
11. Explain WLAN architecture
12. Compare traditional instruments and virtual instruments