Data Throughput; Diagnostics Functions - Omron PRT1-COM Operation Manual

PROFIBUS-DP characteristics

1-4-2 Data throughput

Transmission time

1-4-3 Diagnostics functions

Extensive diagnostics
Device related
diagnostics
Module related
diagnostics
Channel related
diagnostics
6
At 12 Mbit/s, PROFIBUS-DP requires approximately 1 ms for the transmission
of 512 bits of input data and 512 bits of output data distributed over 32 stations.
The figure below shows the typical PROFIBUS-DP transmission time
depending on the number of stations and the transmission speed. The data
throughput will decrease when more than one master is used.
Bus cycle time vs number of slaves
Conditions: Each slave has 2 bytes of input data and 2 bytes of output data.
The extensive diagnostic functions of PROFIBUS-DP enable fast location of
faults. The diagnostic messages are transmitted over the bus and collected at
the master. These messages are divided into three levels:
• Device related diagnostics
This diagnostic level concerns the general operational status of the whole
device (e.g. overtemperature or low voltage).
• Module related diagnostics
This diagnostic level indicates that a fault is present in a specific I/O range
(e.g. an 8-bit output module) of a station.
• Channel related diagnostics
This diagnostic level indicates an error at an individual input or output (e.g.
short circuit on output 5).
Section 1-4