3 Detailed checklist
Checklist
Article ID: 109745536, V2.0, 05/2022
18
©
S
iem
e
n
s A
G
2
0
2
2
A
ll r
igh
ts
re
se
rv
e
d
MRP Interconnection
The "MRP Interconnection" protocol is an extension of MRP that enables the
redundant coupling of two or more MRP rings. Isochronous realtime (IRT) networks
are excluded from this. A very fast reconfiguration is possible with MRP
Interconnection; the reconfiguration time is typically less than 200 milliseconds.
Note
The "MRP Interconnection" function is only available in MSPS devices.
Factory settings
When they arrive from the factory, almost all SCALANCE X components already
have the ring ports enabled by default. You can find the precise port numbers in
the corresponding manuals for the various hardware models. The P1/P2 ports,
optical ports or gigabit ports are common.
"Automatic Redundancy Detection" ("ARD") is the preset. A device with ARD
enabled behaves as follows:
•
If an HRP manager is connected, the device becomes an HRP client.
•
If an MRP manager is connected, the device becomes an MRP client.
•
If no ring manager is connected, the device becomes an MRP manager.
•
ARD will never cause the device to become an HRP manager.
Menu path
You can find this information in the following paths:
•
With MSPS: "Layer 2 > Ring Redundancy"
•
With X-200 and X-300: "X200 / X300 > Ring (Redundancy)"
Recommendation
If the device is not being operated in a ring, disable ring redundancy.
Note
With the default "ARD" preset, a SCALANCE X device will itself become the MRP
manager if there is no ring manager connected. This function sends test frames at
both of the ring ports which monitor the state of the ring. The test frames are MAC
multicasts. Most devices will interpret these frames as an unknown multicast and
flood it to all other ports accordingly.
Depending on the structure, this may cause errors, for example with other ring
managers or if devices receive too many multicasts overall.
The "Link Check" feature can be enabled for optical ports in order to detect partial
interruptions in the connection (if available in the device).
