This diagnostic repeater is a repeater with the ability to monitor a segment of an
RS 485 PROFIBUS subnet (copper wire) during running operation and to signal
line faults via diagnostic message to the DP master. By means of STEP 7, COM
PROFIBUS and operator interface systems (SIMATIC HMI) the location and cause
of fault can be displayed in plain text.
Through its line diagnostics during operation the diagnostic repeater allows line
faults to be rapidly detected, localized, and visualized. In this way, problems in
plants can be detected in good time and system standstills minimized.
Functions of the diagnostic repeater
The diagnostic repeater fulfills the following tasks:
Diagnostic function for two PROFIBUS segments (DP2 and DP3):
The diagnostic function supplies the fault location and the fault cause of line faults, such as a wire break or missing matching resistors.
The fault location is specified relative to the existing nodes, for example "Shortcircuit in the signal line A against shield between Nodes 12 and 13".
Repeater function for three PROFIBUS segments (DP1, DP2 and DP3):
The diagnostic repeater amplifies data signals on bus lines and links individual RS 485 segments.
Programming device isolated galvanically or electrically from the other bus segments. When the programming-device line is withdrawn/plugged, no fault is caused at the other segments of the PROFIBUS-DP, even at high baud rates.
The diagnostic repeater is a DP slave with an IP 20 degree of protection.
New functions of the diagnostic repeater
The diagnostic repeater with the order number 6ES7 972-0AB01-0XA0 offers the following new functions:
It allows the stored topology table to be read out and the bus topology to be visualized via STEP 7.
It allows stored diagnostic and statistical information to be read out.
It maintains a clock that can be set and read by the user program.
It offers monitoring functions for the clocked PROFIBUS bus system.
It makes identification data available.
Range of application of the diagnostic repeater
A diagnostic repeater is required for:
Line diagnostics of the PROFIBUS network during running operation
The connection of more than 32 nodes to the bus
The implementation of branches
The control-to-load isolation between two segments
The ungrounded operation of bus segments
The visualization of the bus topology via STEP 7 as of V5.2