EDS-405A/408A Series User’s Manual
Featured Functions
3-21
Using Communication Redundancy
Setting up Communication Redundancy on your network helps protect critical links against failure,
protects against network loops, and keeps network downtime at a minimum.
The Communication Redundancy function allows the user to set up
redundant loops
in the
network to provide a backup data transmission route in the event that a cable is inadvertently
disconnected or damaged. This is a particularly important feature for industrial applications, since
it could take several minutes to locate the disconnected or severed cable. For example, if the
EDS-600 is used as a key communications component of a production line, several minutes of
downtime could cause a big loss in production and revenue. The EDS supports three different
protocols to support this communication redundancy function—
Rapid Spanning Tree/
Spanning Tree Protocol (IEEE 802.1W/1D),
Turbo Ring
,
Turbo Ring V2
and
Turbo Chain
.
When configuring a redundant ring, all switches on the same ring must be configured to use the
same redundancy protocol. You cannot mix the “Turbo Ring,” “Turbo Ring V2,” and STP/RSTP
protocols on the same ring. The following table lists the key differences between each feature. Use
this information to evaluate the benefits of each, and then determine which features are most
suitable for your network.
Turbo
Ring
V2
Turbo Ring
Turbo Chain STP
RSTP
Topology
Ring Ring Chain
Ring,
Mesh
Ring,
Mesh
Recovery Time < 20 ms
< 300 ms
< 20 ms
Up to 30 sec. Up to 5 sec
NOTE
Most of Moxa’s managed switches now support three proprietary Turbo Ring protocols:
(1)
“Turbo Ring”
refers to the original version of Moxa’s proprietary redundant ring
protocol, which has a recovery time of under 300 ms.
(2)
“Turbo Ring V2”
refers to the new generation Turbo Ring, which has a recovery time
of under 20 ms.
(3)
“
Turbo Chain
” is a new Moxa proprietary protocol with unlimited flexibly to allow you
to construct any type of redundant network topology. The recovery time is under 20 ms.
In this manual, we use the terminology
“Turbo Ring” ring
and
“Turbo Ring V2” ring
to
differentiate between rings configured for one or the other of these protocols.
Gigabit Ethernet Redundant Ring Capability (< 50 ms)
Ethernet has become the default data
communications medium for industrial automation
applications. In fact, Ethernet is often used to
integrate video, voice, and high-rate industrial
application data transfers into one network. The
EDS-600, which comes equipped with a redundant
gigabit Ethernet protocol called Gigabit Turbo
Ring, gives system maintainers a convenient means
of setting up a versatile yet stable gigabit Ethernet
network. With Gigabit Turbo Ring, if any segment
of the network gets disconnected, your automation
system will be back to normal in less than 300 ms
(Turbo Ring) or 50 ms (Turbo Ring V2).
Gigabit Turbo Ring
Recovery Time < 50 ms
