ISA Certified Automation Professional (CAP) program

  • Certification Review

Certified Automation Professionals (CAPs) are responsible for the direction, design, and deployment of systems and equipment for manufacturing and control systems.

CAP question

All of the following capabilities would be considered to be Ethernet Industrial Protocol (EtherNet/IP®) advantages EXCEPT:

A. non-deterministic nature.
B. open network standards.
C. lower component costs.
D. broad usage and support.
 

CAP Answer

The answer is A: "Non-deterministic nature".

EtherNet/IP® is designed for control applications that can accommodate a measure of non-deterministic data transfer, but it is significantly more robust and deterministic than standard Ethernet and TCP/IP.  Ethernet/IP® has all of the advantages of "standard" ethernet, such as low-cost switches and cabling/connectors, broad usage and support, and a set of open network standards that allow devices from different manufacturers to be used on the same network. 

On a properly designed network, Ethernet/IP® can approach the reliability of a deterministic protocol when command disagree alarms and other command confirmation strategies are employed.

Reference: Trevathan, Vernon L., A Guide to the Automation Body of Knowledge, 2nd Ed., 2006

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