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11/12/2019
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7 Media Redundancy (MRP) / Fast Start-Up (FSU)
The measuring system supports the
Media Redundancy Protocol
(MRP) according to IEC 62439
as well as the
Fast Start-Up
(FSU) function for optimized system start-up.
However, only one of the two functions can be used at the same time. When configuring the system,
you must therefore decide which of the two functions should be used.
7.1 MRP
To increase the availability, industrial communication networks are designed with redundant physical
connection paths between the network nodes.
The Media Redundancy Protocol ensures a loop-free network topology and detection of
communication interruptions.
The system and machine availability is significantly increased by the redundant network structure, as
the failure of individual devices has no effect on the communication.
Maintenance and repair work no longer require a system shutdown and can be performed during
operation.
The measuring system is integrated into the ring topology as an MRP client and is monitored by the
MRP manager.
Installation guidelines
● All ring nodes must support MRP and have the MRP protocol activated.
● Connections in the ring must be connected via the configured ring ports.
● The maximum number of ring nodes is 50. Otherwise reconfiguration times > 200 ms can result.
● All devices connected within the ring topology must be members of the same redundancy domain.
A device cannot belong to several redundancy domains.
● All devices in the ring must be set to "MRP Client", "MRP Manager (Auto)/Client" or "Automatic
Redundancy Detection". At least one device in the ring must have the setting "MRP Manager
(Auto)/Client" or "Automatic Redundancy Detection".
● All partner ports within the ring must have the same settings.
Also see
SIEMENS Entry ID: 109739614
.
7.2 FSU
Fast Start-Up (FSU) is an optimized system start-up, which enables much quicker access to data
exchange from the second start-up. This is done by permanently storing many parameters, so that
they do not need to be re-transmitted during start-up.
In order to achieve optimized start-up times, the Auto-Negotiation and Auto-Cross-Over functions must
be deactivatable at the relevant switch of the network node. To enable a connection however, a
crossover cable or a switch with port wiring is required for crossing the connections.
Also see
PROFINET Design Guidelines, PNO order no.: 8.062.
