CPE Profibus Network Architecture & Design 5

Question 1

What is the maximum total number of stations supported across an entire Profibus DP network (using repeaters)?

Accepted Answer

126

Answer

Profibus DP supports a maximum of 126 stations across the entire network (addresses 0–125), regardless of the number of segments or repeaters used.

Question 2

In a Profibus network with multiple masters, how is bus access arbitrated between Class 1 masters?

Accepted Answer

Token passing in ascending address order

Answer

Multiple Profibus masters share the bus using a logical token ring where the token is passed in ascending station address order, granting each master a turn to communicate.

Question 3

Which Profibus DP feature allows a slave to notify the master of an alarm or event without waiting to be polled?

Accepted Answer

DP-V1 alarm acknowledgment mechanism

Answer

DP-V1 introduced an alarm mechanism where slaves can signal alarms to the master, and the master must explicitly acknowledge receipt of each alarm.

Question 4

When installing Profibus RS-485 cable near high-voltage power cables, what minimum separation distance is generally recommended?

Accepted Answer

20 cm

Answer

A minimum separation of 20 cm (200 mm) between Profibus cables and high-voltage power cables is generally recommended to reduce electromagnetic interference.

Question 5

What is the purpose of the 'Ident_Number' field in a Profibus GSD file?

Accepted Answer

Uniquely identifies the slave device type to the master

Answer

The Ident_Number is a unique 2-byte identifier assigned by the Profibus organization that identifies the specific device type, allowing masters to verify correct device configuration.

(CPE) Certified Profibus Engineer Practice Test

(CPE) Certified Profibus Engineer Practice Test

CPE Profibus Network Architecture & Design 5