CAS CAS Automation Specialist Network Communications & Protocols 3

Question 1

In PROFINET IO, what is the role of the IO Controller?

Accepted Answer

It runs the automation program and communicates with IO Devices

Answer

The IO Controller (typically a PLC) runs the user program and exchanges cyclic process data with IO Devices (field devices) over the PROFINET network.

Question 2

Which feature of managed industrial Ethernet switches is critical for ensuring real-time performance in motion control applications?

Accepted Answer

IEEE 1588 Precision Time Protocol (PTP) support

Answer

IEEE 1588 PTP allows sub-microsecond clock synchronization across networked devices, which is essential for coordinated motion control applications.

Question 3

What does the acronym 'CIP' stand for in the context of EtherNet/IP and DeviceNet?

Accepted Answer

Common Industrial Protocol

Answer

CIP (Common Industrial Protocol) is the application layer protocol shared by EtherNet/IP, DeviceNet, and ControlNet, providing a unified object model for automation devices.

Question 4

In industrial networking, what is the primary advantage of using a ring topology with Media Redundancy Protocol (MRP)?

Accepted Answer

Automatic network recovery within milliseconds after a cable break

Answer

MRP enables ring networks to automatically reconfigure and restore communication in less than 200 ms (typically under 20 ms) after a single network fault.

Question 5

Which function block in IEC 61131-3 is commonly used to send explicit Modbus TCP read requests from a PLC to a remote device?

Accepted Answer

MODBUS_CLIENT

Answer

The MODBUS_CLIENT function block (as defined in IEC 61131-3 and vendor implementations) handles explicit Modbus TCP requests, specifying function codes, register addresses, and data.

(CAS) Certified Automation Specialist Practice Test

(CAS) Certified Automation Specialist Practice Test

CAS CAS Automation Specialist Network Communications & Protocols 3