Active components
4.1 Active components for RS485 networks
PROFIBUS Network Manual
78 System Manual, Edition 04/2009, C79000-G8976-C124-03
Properties of the diagnostic repeater
The diagnostic repeater performs the following tasks:
● Diagnostic function for two PROFIBUS segments (DP2 and DP3):
The diagnostic function supplies the location and cause of cable problems such as wire
breaks or missing terminating resistors. The location of the problem is specified relative to
the existing nodes, for example "short circuit of signal line A to shield between node 12
and 13".
● Repeater function for three PROFIBUS segments (DP1, DP2, DP3):
The diagnostic repeater amplifies data signals on bus cables and connects individual RS-
485 segments.
● Support when reading out the stored topology table and visualization of the bus topology
with STEP 7.
● Support when reading out the stored diagnostic and statistical information.
● Provides a clock that can be set and read be the user program.
● Provides monitoring functions of PROFIBUS in isochronous mode.
● Provides identification data.
● PG interface electrically isolated from the other bus segments, removing/inserting the PG
connecting cable does not cause disturbances on the other PROFIBUS DP segments
even at high transmission speeds.
● The diagnostic repeater is a DP slave with degree of protection *IP20.
Application of the diagnostic repeater
A diagnostic repeater is necessary for the following:
● Cable diagnostics of a PROFIBUS network during ongoing operation
● Attachment of more than 32 nodes on the bus
● Implementation of branches
● Electrical isolation of two segments
● Ungrounded operation of bus segments
● Visualization of bus topology with STEP 7 as of V5.2.
Order no.
6ES7 972-0AB01-0XA0
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