Two Controllogix Processors Through One ENBT?

Hi Guys

Anyone tried this?

here is the story we have an Ethernet I/P network on site with a controllogix chassis with an L62 controlling the I/O: AENET's PF70's, PV+, ETC.

This controller has about 5 seperate tasks, and now shutting down for changes means downtime for a lot of plant.

I have decided for the next system to be added to this Controlligix Chassis to add another L62 to save more on the above problem.

Now the L62 at the moment communicates with the I/O through a ENBT/A module. The new L62 will be in the same chassis as the ENBT and the old L62

The question is can both controllers communicate through the ENBT with seperate I/O, i.e. the ENBT will be in the I/O tree in both controller but the I/O will only be in one controller.

I have asked tech support in the UK they are going to find out / test as they are not sure.

I know I could use produced/consumed tags. however this will still mean shutting down the old L62 when adding I/O to the new one.

the other option is another ENBT in the chassis but a bit expensive if not needed

Thanks in advance


cheers

myles

Yes - of course you will need to confirm that your communications has not exceeded the recommended limits and connections.

thanks for your responce, at the moment there is 20 seperate IP Addresses on this network, i am unsure as to count connections, but i will look into it, and the limits of this card.

so when configuring the ENBT card in the new controller just call it the same and set it up as per the settings in the first?

very happy with that answer saves a fair bit cash!

Many Thanks

cheers

myles

You can try out Rockwell's EthernetIP Performance Prediction Tool to see what kind of load you have: http://www.rockwellautomation.com/solutions/integratedarchitecture/get/EtherNetIPSetup.zip

The newer EN2T will handle a lot more traffic than the ENBT.

I am curious about what would happen if the ENBT settings in the second controller's project were different from the first and then you do a download.

Would the ENBT be reconfigured with the new settings and it would fault out in the first controller?

When you setup the local ENBT in the RSLogix5000 I/O Configuration there really aren't settings to be downloaded. The offline configuration of the IP address and subnet mask are not downloaded to the module. When a download is performed the download is done to the controller, not the ENBT.

I have used two controllers with one ENBT several times. The settings can be different as long as they both point to the same slot #. Different names are ok.

The biggest issue is certainly exceeding the packet limit and the connection limit of the ENBT. I would seriously consider moving to the EN2T for the increased bandwidth it provides.

OG

thanks for all taking the time to post your answers!

i will put this together and test it this week.

there is at the moment not that much on this network, thanks for the link to the performance prediction tool i have downloaded it but still have to gather the info it needs.

the EN2T sonuds like it may be needed later on in the life of this system, the rack also has another ENBT that is connected to the company intranet, control room computers and my desk for editing.

i read the litrature on the EN2T about not using Rack optimised connections if the two modules are in the same chassis, any one any idea why?

is that optimised in the EN2T or the ENBT, as the one on the intranet does not have I/O connected if we upgraded it would only be the EN2T that had the optimised connections.

I believe this is possible, and I can check this out tomorrow.

Possible pitfalls are "multiple ownership" issues, but since there is no "Configuration" tag created when you put the ENBT into the I/O configuration, it should be Okay.

I will post back with result of test.


HA ! I see I cross post....Like I said it should be possible...

tech support got back to me on this yesterday!

here is their responce

YES. You can.

Just make sure none of the IO is mapped in the other Clx. The 1794-AENT and the IO are individually owned.

this confirms what you guys beat them to! many thanks!

cheers

myles