Redundant system

Hello!

We have a following project on development phase:
19 substations, included Flex IO, CLX, SCADA.
For IO's we want touse ethernet optical ring. But as it must be quite rliable, we need sort of redundancy. Is it possible at all, if we use Ethernet IO's with AB PLC? Is there any ControlNet <-> Ethernet/IP gateway or conwerter?

BR
Lauri

hi,

informations given are too limited to comment.

Modicon do have bus redundancy architecture. I think u can visit www.modicon.com .

I can fully understand why you want to use Ethernet I/O, it is very easy to configure and does not require scheduling with RSNetworx.

But I would think that if you need redundant cabling then ControlNet is still the best way to go. Every ControlNet module has a fully redundant option, ie 1756-CBBR that is built in at the module level. This allows for a passive totally redundant cabling scheme that makes no other demands on the system and requires no extra configuation. This is simply not available with 1756-ENBT Ethernet equivalent.

Also setting up Ethernet rings with fully redundant paths is non-trivial. Plus the Ethernet switches are active nodes in the system which don't add to reliablity.

ControlNet can be implemented in FibreOptic very easily, and although the purchase price is higher than with Ethernet, the total cost of getting it all going is likely to be about the same.

One way of getting a very nice F/O ControlNet redundant system is to use TWO sets of F/O modems in a star configuraton, rather than a ring.

One final point ...I am not sure which Version maybe 13 or 14, but RA plan to allow ControlLogix to use ControlNet I/O WITHOUT the the need for RSNetworx to schedule. Will makelife a lttle simpler for those who don't need the strict deteminism the scheduling offers.

Thanks to all. Yesterday the people above me took decision that there will be Ethernet ring, Flex IOs and two CLX, each of them controlling half the system. So no redudancy in PLC side at all. The reason why they took Ethernet was, that then thre is possible to send some other data also throw it (like video, etc). First offer was red. ControlNet with Ex IO's but the customer didnot want Ex (even it would be excellent solution). Anyway, that's life.


BR
Lauri

They want reliability on their Ethernet network, but they're throwing non-control traffic on it as well ?

[sigh].

Strange, isn't it? Sadly it's still common in Estonia - count every penny, no matter how it affects the system.