Siemens S7-300 Configuration Manual page 75

● You want to use MRP in a ring topology that also includes non-Siemens devices or you
● You want to disable MRP:
Ring port 1 / ring port 2
Here, select the port you want to configure as ring port 1 and ring port 2.
With devices with more than 8 ports, not all ports can be selected as ring port.
The drop-down list shows the selection of possible ports for each device type. If the ports are
specified in the factory, the boxes are grayed out.
NOTICE
Ring ports after resetting to factory settings
If you reset to the factory settings, the ring port settings are also reset.
• CPs adopt the "Manager (Auto)" MRP role.
• With switches, the redundancy method Automatic Redundancy Detection (ARD) is
If other ports were used previously as ring ports before resetting, with the appropriate
attachment, a previously correctly configured device can cause circulating frames and
therefore the failure of the data traffic.
Configuring and commissioning S7 CPs for Industrial Ethernet
Configuration Manual, 09/2013, C79000-G8976-C182-13
want to receive diagnostic interrupts relating to the MRP status from a device (see
"Diagnostic interrupts"):
– Assign precisely one device in the ring the role of "redundancy manager".
– For all other devices in the ring topology, select the role of "Client".
Note
To ensure problem-free operation when using a non-Siemens device as the
redundancy manager in the ring, make sure that you assign the fixed role of "Client" to
all other devices in the ring, before you close the ring. Otherwise, there may be
circulating data frames that will cause a failure in the network.
Select the option "Not node in the ring" if you do not want to operate the device within a
ring topology with MRP.
Note
Role after resetting to factory settings
Brand new Siemens devices and those reset to the factory settings have the MRP role
"Manager (Auto)" (CPs) or "Automatic Redundancy Detection" (SCALANCE X). If you are
operating a non-Siemens device as the redundancy manager in the ring, this may cause
loss of the data traffic.
activated.
Configuring the Ethernet CP with STEP 7
3.5 Media redundancy
75