THEORY EXAMINATION (SEM–VI) 2016-17 INTELLIGENT INSTRUMENTATION

INTELLIGENT INSTRUMENTATION (EEE022)

SECTION – A

(10 × 2 = 20 Marks | Short Answers)

a) Software Based Instruments

Software-based instruments are measurement systems where most instrument functions (display, processing, analysis) are implemented using software on a computer instead of dedicated hardware.

b) String

A string is a sequence of characters used to represent text data such as names, commands, or messages in programming and instrumentation software.

c) Use of DMA (Direct Memory Access)

DMA allows data transfer directly between I/O devices and memory without continuous CPU involvement, improving speed and system performance.

d) Applications of Intelligent Instrumentation

Applications include industrial automation, medical instruments, aerospace systems, robotics, process control, data acquisition, and smart sensors.

e) Advantages of Virtual Instruments

Virtual instruments are flexible, cost-effective, easily upgradable, user-friendly, and capable of complex data analysis and visualization.

f) Use of Data Socket

Data Socket is used to share live data between applications or systems using network protocols, enabling real-time data communication.

g) Formula Code

Formula code is a text-based programming block used to perform mathematical calculations and logical operations within virtual instrumentation software.

h) Expand PCMCIA

PCMCIA – Personal Computer Memory Card International Association

i) Commonly Used Operating Systems for PC Hardware

Common operating systems include Windows, Linux, UNIX, and macOS.

j) Role of Filters in Signal Analysis

Filters remove unwanted noise, separate frequency components, improve signal quality, and enhance measurement accuracy.

SECTION – B

(Attempt Any Five | 5 × 10 = 50 Marks)

a) Classification of Intelligent Instrumentation & Current Status

Intelligent instrumentation can be classified into:               Smart sensors

Software-based instruments                                                Networked instruments

Virtual instruments

Current Status:
Modern intelligent instruments integrate microprocessors, communication interfaces, self-calibration, self-diagnosis, and AI-based decision making, making them highly accurate and adaptive.

b) Code Interface Nodes – Purpose & Working

Code Interface Nodes allow integration of text-based programming languages (like C/C++) with graphical programming environments.

Working:
They accept input parameters, execute user-defined code, and return output values to the graphical program, enabling complex algorithm implementation.

c) RS-423 Bus Diagram & Working

RS-423 is a serial communication standard similar to RS-232 but supports higher data rates and longer distances.

Working:
It uses unbalanced voltage signaling with one transmitter and multiple receivers. Data is transmitted serially with start, data, parity, and stop bits.

d) Interfacing Methods of DAQ Devices with Computers

DAQ devices can be connected using:                           USB

PCI / PCIe                                                                        PXI

Ethernet

Software Structure:
Includes drivers, application software, data acquisition libraries, and user interface for data processing and display.

e) VI Loops, Charts, Arrays, Graphs & Clusters

Loops: Repeated execution (For, While loops)

Charts: Display real-time data

Arrays: Store multiple data values

Graphs: Display waveform or XY data

Clusters: Group different data types together

f) Data Flow & Graphical Programming Techniques

Graphical programming uses data flow concepts, where execution depends on data availability rather than sequence.

Advantages:
Easy visualization, parallel execution, intuitive design.

Limitations:
Large programs become complex, less suitable for very low-level programming.

g) Historical Perspective of Intelligent Instrumentation

Instrumentation evolved from analog instruments to digital systems, then microprocessor-based instruments, and finally to virtual and intelligent instruments with networking and AI capabilities.

h) PXI Controller & Its Types

A PXI controller is the central processing unit of a PXI system.

Types:

Embedded PXI controllers

Remote PXI controllers

They provide control, data processing, and communication for modular instrumentation systems.

SECTION – C

(Attempt Any Two | 2 × 15 = 30 Marks)

3) Interrupts in Serial/Parallel Interfacing

Interrupts allow devices to request CPU attention.

Types:                                                Hardware interrupts

Software interrupts                            Maskable interrupts

Non-maskable interrupts

Serial Interface Interrupts:
Generated during data transmission or reception.

Parallel Interface Interrupts:
Generated when data is ready or handshake signals change.

Timing Diagrams:
Show relationship between data lines, control signals, and interrupt request timing.

4) Short Notes

(i) String and File Input-Output

String I/O handles text data, while file I/O allows reading and writing data to storage files for logging and analysis.

(ii) DLL Links

Dynamic Link Libraries (DLLs) store reusable code that can be called by multiple applications, reducing memory usage.

(iii) Counters

Counters count events, pulses, or occurrences and are widely used in frequency measurement and timing applications.

(iv) Timers

Timers measure time intervals, generate delays, and control event sequencing in instrumentation systems.

5) Short Notes

(i) RS-232C

A serial communication standard for short-distance, low-speed data transmission using unbalanced signaling.

(ii) RS-422

Uses differential signaling, supports higher data rates and longer distances than RS-232.

(iii) RS-485

Supports multiple transmitters and receivers on a single bus, widely used in industrial communication.

(iv) IEEE-488.1 & IEEE-488.2

Also known as GPIB standards, used for communication between instruments and controllers. IEEE-488.2 defines data formats and protocols.