6-4
PACSystems* RX3i PROFINET Controller Manual
– December 2011
GFK-2571A
6
Ring Topology with One Controller
The diagram below illustrates a simple ring topology with one RX3i CPU Node and three IO-Devices
on the same PROFINET network. In this example, the PNC module in the RX3i controller is
configured to be the Media Redundancy Manager and the IO-Devices, in this case VersaMax PNS
modules, are configured to be Media Redundancy Clients.
IO LAN 1
RX3i CPU Node with
PROFINET Controller
IO-Device
IO-Device
IO-Device
As a Media Redundancy Manager, the PNC detects when the network ring has been broken and
repaired. Each time the PNC detects that the ring has been broken or repaired, a fault is reported in
both the Local Log and RX3i I/O
CPU’s fault table. In addition, the PNC keeps a count of
break/repair detections, which can be viewed via the PNC
’s Command Line Interface using the
show
rdnmedia
command.
As a Media Redundancy Manager, the PNC detects whether another Media Redundancy Manager
is on the same ring. If more than one Media Redundancy Manager is present on the same ring, the
PNC logs an entry in its local log table and also in the RX3i fault table. Upon detecting that there are
no longer multiple Media Redundancy Managers on the ring, the PNC also logs a fault (in the local
log and RX3i fault table) to indicate that the invalid setup has been resolved.
