CPE Communication Protocols & Standards 4

Question 1

What is the purpose of the Slave Diagnostic Data in PROFIBUS DP?

Accepted Answer

Reports module-level faults, configuration errors, and device-specific status to the master

Answer

PROFIBUS DP slave diagnostic data provides structured fault information including station, module, and channel-level diagnostics to the Class 1 master.

Question 2

Which profile defines how PROFIBUS devices communicate in process automation applications involving transmitters and positioners?

Accepted Answer

PA Profile 3.02

Answer

The PA Profile (currently version 3.02) standardizes device descriptions and data formats for process automation instruments on PROFIBUS PA.

Question 3

In the PROFIBUS protocol stack, which layer handles data sequencing and segmentation?

Accepted Answer

PROFIBUS uses only Layers 1, 2, and 7; Layers 3-6 are not used

Answer

PROFIBUS implements only the Physical (Layer 1), Data Link (Layer 2), and Application (Layer 7) layers of the OSI model, omitting Layers 3–6.

Question 4

What is the function of the Sync command in PROFIBUS DP?

Accepted Answer

Forces slaves to hold their output values until a new Sync or Unsync command

Answer

The Sync command instructs a group of slaves to freeze their current output states, ignoring new output data until Unsync is issued.

Question 5

Which mechanism does PROFIBUS DP use to detect a lost slave device?

Accepted Answer

Watchdog timer on the slave that resets outputs if no valid message is received within a configured time

Answer

PROFIBUS DP slaves have a configurable watchdog timer that triggers a safe-state output condition if no valid cyclic data frame is received within the timeout period.

(CPE) Certified Profibus Engineer Practice Test

(CPE) Certified Profibus Engineer Practice Test

CPE Communication Protocols & Standards 4