Metel 1-988-220, Quick Installation Manual

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LAN-RING for Ring Topology
One of the fundamental elements of the security system LAN-RING is fast data forwarding to a back-up
line. Since 2008, this function has been performed by LAN-RING.v1 protocol with a switchover time of
30ms from the failure. Each ring in the system has a unique ID and one switch with the MASTER function
(controls the ring). The higher port of the MASTER switch is normally set to a BLOCKING mode, hence
preventing a loop. A port in BLOCKING mode receives only LAN-RING frames and blocks the other data
(back-up line). If a failure occurs, the state of the blocked port changes to FORWARDING and starts to
transmit all data.
Initial State Failure Failure Resolution Final State
During the failure creation and resolution, there are 2 short interruptions in the route. The second
interruption provides the switchover from the back-up line back to the MASTER switch. Since, the end
of 2014, a new innovative version of LAN-RING.v2 is available. The switch which has the MASTER function
which controls the ring. In the case of a failure, the MASTER function moves to the switch next to the
failure. From the origin of the problem to the time of its removal, only one interruption occurs of up to
maximum of 30ms.
Initial State Failure Failure Resolution = Final State
&
The switchover time to the back-up line is for LAN-RING protocols slightly dependent
on the number of switches connected in the ring. With each switch connected to the ring,
the reconfiguration time increases by only about 6μs!
MASTER
MASTER
MASTER MASTER MASTER
Interruption
When a Failure
Occurs
Interruption
During Failure
Resolution
MASTER MASTER
Port in
BLOCKING
Mode
Port in
BLOCKING Mode
Interruption
When a
Failure
Occurs
RSTP and RSTP-M for MESH Topology
The RSTP-M protocol is a time-optimized version of
the general RSTP protocol with which it is backward
compatible. In addition, it meets the requirements of
safety and automation systems to quickly secure a
backup route in the event of a fault and:
v
is fully compatible with RSTP according to IEEE
802.1D-
2004
v
supports MESH topology
v
reduces reconfiguration times to a minimum
DP
DP
DP
DP
DP
DP
RP
RP
RP
RP
RP
BP
BP
RP
RP – root port
DP – designated port
BP – blocked port
Redundant Topology