Artificial Intelligence Notice: ISA prohibits the entry of ISA standards and related ISA intellectual property (“ISA IP”) into any form of Artificial Intelligence (AI) tools, such as ChatGPT. Additionally, creating derivatives of ISA IP using AI is also prohibited without express written permission from ISA’s CEO. In the case of such use, ISA will suspend a licensee’s access to ISA IP, and further legal action will be considered. Please review ISA's Terms and Conditions for further information.

  • CCST
ISA Certified Control Systems Technician (CCST) program

Certified Control System Technicians (CCSTs) calibrate, document, troubleshoot, and repair/replace instrumentation for systems that measure and control level, temperature, pressure, flow, and other process variables.

CCST question

All of the following instrumentation bus networks can be implemented with a single pair of wires, except for?

A. Foundation Fieldbus
B. DeviceNet
C. AS-i
D. HART

CCST Answer

The correct answer is B, "DeviceNet." Foundation Fieldbus (FFB), Actuator-Sensor Interface (AS-i), and Highway-Addressable Remote Transducer (HART) instrument bus networks all operate over a single pair of wires. The power for the transmitter and the communication signal are both carried over that single pair of wires.

DeviceNet requires a separate pair of wires for power and signal, with an additional shield/ground wire. DeviceNet, then, typically requires five conductors (two pairs and a shield/ground).

Reference: Goettsche, L.D. (Editor), Maintenance of Instruments and Systems, Second Edition, ISA, 2005.

Reader Feedback


We want to hear from you! Please send us your comments and questions about this topic to InTechmagazine@isa.org.



Like This Article?

Subscribe Now!

About The Author