LEC 5 IOT Flashcards
(13 cards)
What are the three main transmission protocols in Arduino?
Serial (UART) - Asynchronous, full-duplex, one-to-one communication.
SPI (Serial Peripheral Interface) - Synchronous, full-duplex, master-to-multiple slaves.
I²C (Inter-Integrated Circuit) - Synchronous, half-duplex, multi-master to multi-slave communication.
What was the evolution of industrial automation?
Started with Pneumatic Controllers using pressurized air.
Transitioned to Electrical Controllers (cheaper, faster, more reliable).
Adoption of 4-20mA Current Signal for better noise immunity.
Modern Field Bus Protocols (for longer distances, higher data rates, and faster response times).
Why are Field Bus Protocols needed?
Longer Distance (up to 71 km).
Higher Data Rates (10–100 Mbps).
Faster Response Time (0.1–1 ms).
Supports More Devices (up to 1000).
What is the difference between Brownfield and Greenfield systems?
Brownfield: Uses legacy equipment and traditional methods.
Greenfield: New systems built from scratch, compatible with Industry 4.0.
What is the significance of 4-20mA current signals?
Uses electrical current as a signal instead of voltage.
4mA = 0% signal, 20mA = 100% signal.
More resistant to electrical interference compared to voltage-based signals.
HART Protocol (Highway Addressable Remote Transducer) is an extension of this.
What is the difference between Proprietary and Open Protocols?
Proprietary Protocols: Closed, hidden from the public.
Open Protocols: Published publicly, can be freely used or licensed.
What is Modbus and where is it used?
Client-server communication protocol for industrial devices.
Modbus RTU: Uses RS485 for serial communication.
Modbus TCP: Uses Ethernet/WiFi (port 502).
Used in SCADA (Supervisory Control And Data Acquisition) and PLCs (Programmable Logic Controllers).
What are the Modbus data models and their functions?
Discrete Input (Single-bit, Read-only) → Provided by an I/O system.
Coils (Single-bit, Read-Write) → Can be altered by an application program.
Input Registers (16-bit, Read-only) → Provided by an I/O system.
Holding Registers (16-bit, Read-Write) → Can be altered by an application program.
What is RS485 communication and why is it useful?
Uses differential voltage referencing for long-distance transmission.
Supports half-duplex and full-duplex communication.
Used in industrial automation, PLC systems, and SCADA.
What are the three types of transmission directions?
Unidirectional: Data flows only in one direction.
Bidirectional, Half-Duplex: Devices can send/receive, but not simultaneously.
Bidirectional, Full-Duplex: Devices can send/receive data at the same time.
What are the features of the Arduino Modbus Library v1.0.9?
Supports RS485 (wired) with RTU and Modbus TCP (Ethernet/WiFi).
Uses server-client protocol:
Client (Master) → Initiates requests.
Server (Slave) → Responds to requests.
RTU uses multipoint communication (unique device IDs).
TCP uses point-to-point communication (IP-based).
What is OPC-UA and why is it important?
Standardizes and secures industrial communication from field devices to the cloud.
Enables machine-to-machine (M2M) communication in Industry 4.0.
How is data integrity checked in industrial systems?
Checksums: Sum of all data bytes in hexadecimal (8-bit checksum).
