Vacon optea Installation Manual page 23

Layout and connections
In the example below, the Ethernet communication will be interrupted to device number three and
other devices after that when the link is broken.
DRIVE
OPTE9-1
NOTE! MRP (as MRC) can only be used when PROFINET IO is the selected protocol. MRP is available
in all versions of OPTEA board and in OPTE9 since V006 firmware.
MRP Recovery Times and Fast MRP
MRP can be configured to send test frames with different time periods, depending on the maximum
allowed recovery time for the network. These times are set as the guaranteed time for a network of
50 nodes to recover from a ring error.
Typically, in PROFINET IO systems the recovery time is defined as 200 ms. However, the MRP
specification allows for recovery times of 500, 200, 30 and 10 ms. OPTEA and OPTE9 boards can be
used in systems with the lowest recovery time of 10 ms. This is often called "Fast MRP".
When you use MRP in a PROFINET IO network, we suggest that you set the watchdog time of each
device in the ring to the maximum recovery time, usually 200 ms. This guarantees that a cable
failure does not interrupt the fieldbus connection.
4.4.3.3 Device Level Ring (DLR)
Device Level Ring (DLR) protocol provides a means for detecting, managing and recovering from
faults in a ring-based network. It supports a single-ring topology. Multiple or overlapping rings are
not supported. Other features include "Sign on process" used to identify all ring participants and
"Neighbor check process" which allows nodes to check the health of their adjacent nodes.
One device acts as a ring supervisor, monitoring the state of the ring while other devices act as DLR
nodes. Only one device can act as an active supervisor, although backup supervisors are possible.
Nodes can be divided into Beacon- and Announce-based nodes depending on which frames the
nodes process. OPTEA and OPTE9 boards support Announce-based functionality.
DLR nodes have three states:
• IDLE_STATE: indicating linear topology for non-supervisor nodes
• FAULT_STATE: initial state for enabled ring supervisor, or when ring fault has been detected
• NORMAL_STATE: normal function in ring topology mode
The active ring supervisor sends Beacon frames from both its ring ports once per beacon interval
(400 μs by default) to monitor the state of the ring and an Announce frame once per second. If the
Beacon frames are received back at the supervisor, one of its ports is set to blocking and the other
to forwarding state (Figure 13).
Local contacts: https://www.danfoss.com/en/contact-us/contacts-list/
Forwarding
DRIVE
MRC MRC
OPTE9-2
Figure 12. MRP ring: Error in network
PLC
MRM
Forwarding
DRIVE
MRC
...
OPTE9-3 OPTE9-8
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DRIVE
MRC
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