Contemporary Control Systems Compact Managed Switches Software Manual for Console Access - Manual (Page 42)

TD020850-0MG
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4.3.9.3 RapidRing TM
4.3.9.3.1 Characteristics of RapidRing
RapidRing technology from Contemporary Controls provides high speed redundancy in
Ethernet networks. It allows recovery in under 300 ms. If desired, the ring can consist
of a mixture of 8-port, 16-port and 24-port switches.
RapidRing is wired in a simple ring structure using ports 7 and 8 of each 8-port switch
(as shown in Figure 33) or ports 1 and 2 on each 16- or 24-port switch. Every link in the
ring must connect the odd-numbered ring port (7 or 1) of one switch to the even-
numbered ring port (8 or 2) of the adjacent switch. A properly constructed ring will
never have a link between identical ports of adjacent switches. The ring ports can be
wired with copper or fibre optic cable, depending on the model of switch.
Figure 33 — RapidRing
As shown in Figure 33, one switch must be selected as the “master” that activates the
backup link if a ring failure occurs. The backup link must connect to the master through
its even-numbered ring port which remains inactive during normal network activity. If a
cable failure is detected, the master will activate its backup port to maintain communications.
NOTE: Upon enabling RapidRing, the switch will automatically reboot.
Fault relays and status LEDs work independent of RapidRing. If RapidRing is enabled
and the ring ports are being monitored, the following applies: When a break occurs,
each switch losing connectivity will flash its Status LED and activate its Fault Relay (and
regardless of port monitoring, it will transmit a link-down SNMP trap). The break is thus
located to the link between the two fault-reporting switches. Once the cable is repaired
by the user, the fault relays will disengage and the status LEDs will glow solid to
indicate the ring network is properly connected.
NOTE: A flashing Status LED and Fault Relay activation do not necessarily indicate a ring failure.
The user may also be monitoring non-ring ports — in which case the failure report might indicate a
non-ring issue. However, ring failure in a properly constructed circuit will be reported by two ring
switches — a non-ring issue will not be so reported.