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.
