CCST CCST Communications & Networking in Control Systems

Question 1

Which industrial communication protocol uses a token-passing bus architecture and is commonly found in legacy process control systems?

Accepted Answer

PROFIBUS DP

Answer

PROFIBUS DP uses a token-passing bus architecture that allows deterministic communication in process automation environments.

Question 2

What is the primary purpose of the HART (Highway Addressable Remote Transducer) protocol in process control?

Accepted Answer

Simultaneous analog and digital communication over the same two-wire loop

Answer

HART overlays digital signals on a standard 4–20 mA analog loop, enabling simultaneous analog process variable transmission and digital diagnostics.

Question 3

In an industrial control network, what does the term 'determinism' refer to?

Accepted Answer

The guarantee that messages are delivered within a defined, predictable time frame

Answer

Determinism in industrial networks means that message delivery times are bounded and predictable, which is critical for real-time control.

Question 4

Which OSI model layer is responsible for defining the electrical and physical characteristics of a fieldbus network cable?

Accepted Answer

Physical layer

Answer

The OSI Physical layer defines cable types, connectors, signal voltages, and bit-rate specifications for network media.

Question 5

What is the maximum number of devices that can be addressed on a single HART multidrop network segment?

Accepted Answer

15

Answer

HART multidrop mode supports up to 15 devices on a single segment, with each device set to a unique polling address from 1–15.

(CCST) Certified Control Systems Technician Practice Test