Media Redundancy With Planned Duplication Of Frames (Mrpd; Not For S7-1500R/H) - Siemens SIMATIC ET 200AL System Manual

5.4.3 Media redundancy with planned duplication of frames (MRPD; not for
S7-1500R/H)
MRP extension "Media Redundancy with Planned Duplication of frames" (MRPD)
The MRP extension "Media Redundancy with Planned Duplication of frames" (MRPD) provides
the advantage that, in the case of a failure of a device or a line in the ring, all other devices
continue to be supplied with IO data without interruption and with short update times.
MRPD is based on IRT and MRP. To realize media redundancy with short update times, the
PROFINET devices participating in the ring send their data in both directions. The devices
receive this data at both ring ports so that there is no reconfiguration time.
Requirements for media redundancy with MRPD
• All the devices of the ring must support MRPD, for example interface module
IM 155-6 PN HS as of firmware version 4.0.
• You have configured MRP for all the devices of the ring. You have assigned the MRP role
"Not device in the ring" to devices that are not located in the ring.
• You have configured IRT for all the involved components.
Configuring MRPD
You do not have to explicitly activate MRPD in STEP 7. The function is available automatically
as soon as all the requirements for MRPD are fulfilled.
PROFINET with STEP 7
Function Manual, 05/2021, A5E03444486-AL
5.4 Media redundancy (ring topologies)
Functions
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