connecting 1 controllogix w/ two chassis

Is it possible to have only 1 controllogix w/ two 17-slot chassis using two ethernet modules since there are 30 i/o modules (excluding ethernet module)? I am not sure of this, thus the query. thanks in advance!

Open up Logix5K and give it a try!

The answer is yes, only recommendation is to use two separate 1756-ENBT on the main chassis, one for i/O (second chassis) and the other for info to scada, PC, database etc.

Hi all

I have connected two chassie in the past with Ethernet and had
No problems but I would also have the HMi on the same network
Is this bad idea and is it speed is the main reason I should not
Have done this. It did not effect the machine but I would still
Like to know so the next time I would do it different


Donnchadh

Your best bet is to do Widelto recommended and have one 1756-ENBT for chassis to chassis communications and another for the HMI (and any other connections needed). You'll get the best possible performance from the I/O and the HMI.

@jac - i did not know that if i did it in rs5k it would actually work. like in compactlogix, if i connect 8+ modules in 1 backplane, that would work in rslogix5k but physically I need another power supply.
@Widelto and Firejo - thank you for the post
@Donnchadh - you only used 1 controllogix too right?thanks

Think of it as a networked I/O chassis, not as an "extended backplane".

This is the standard way to connect 1756 type I/O chassis to a ControlLogix CPU.

The best reference document is ENET-UM001, "EtherNet/IP Network Configuration User Manual"

http://literature.rockwellautomation.com/idc/groups/literature/documents/um/enet-um001_-en-p.pdf

@Ken I will read this. I know I still have to read more. Thanks

mike_dr - you have to take a massive leap in moving from, say, PLC or SLC systems to ControlLogix.

In essence, the ControlLogix platform allows you to connect many, many, chassis "together" using a network. That Network can be one or more of many, such as EtherNet or ControlNet.

Once we have our network set-up, it possible for our ControlLogix controller to communicate and use I/O modules in the other chassis. This is not a "Remote I/O" setup in the true sense, since we don't actually have to use all the modules in any remote chassis, just the one's we need.

Now here's an interesting (and exciting, perhaps) scenario... The remote chassis can have one or more controllers in them as well ! In effect, the network just allows us to use the I/O modules in other chassis, i.e. in other locatios.

Going on from that concept, and because the Logix5000 system uses the Producer/Consumer model of data transfer, we are also able to "share" input modules with more than one controller. This is because the input module multicasts (i.e. produces) its input data and status tags to the network. As many controllers in various locations can "consume" those data tags. I have only said that it is possible to "share" input modules, because for obvious reasons output modules cannot be shared, there can only be 1 owner controller of an output module.

@daba - greatly appreciate a small intro about controllogix network which is like a pc terminal-hub architecture. just found out that I need 1783 ETAP to connect pc to a ring network and AB switch 1783-EMS04T for connecting to another group