Control Logix - How Many Ethernet Cards

I'm trying to speck out a CLX system that will have a fair amount of Ethernet I/P comms going on (at least I think). I know you can have multiple EBNT cards in the rack but I'm not sure how to figure out how many I would need.

Comms will be to:

• 2 Panelview Plus HMIs
• 1 connection to 18 Axis Indramat Servo System (no motion will be on this bus. Just status, and boolean start / stop but still, for instance, getting back position and velocity info on 18 axes seems like a good bit of data.
• 9 Powerflex 40 VFD's with Ethernet I/P comms.
• 1 connection to the plant network.

I will have a managed switch in the cabinet to do the IGMP Snooping etc to help with the load.


Any and all suggestions appreciated.


Thanks,

ndzied1 said:

Comms will be to:

• 2 Panelview Plus HMIs
• 1 connection to 18 Axis Indramat Servo System (no motion will be on this bus. Just status, and boolean start / stop but still, for instance, getting back position and velocity info on 18 axes seems like a good bit of data.
• 9 Powerflex 40 VFD's with Ethernet I/P comms.
• 1 connection to the plant network.

Click to expand...

First break for me would be I/O vs non-I/O. Your Ethernet/IP traffic on one network, everything else on the other network. I think I'd put the servo system on the I/O network.

Bandwidth is probably not an issue. Keeping I/O traffic off the plant network will keep the IT guys off your back. The other consideration is, what do you need remote access to? I'd put the PLC and the Panelviews on the plant network for that reason. That may drive your decision for the servo system as well.

You could even do this with one ethernet card and a managed switch, but I prefer physically separate networks.

http://www.rockwellautomation.com/solutions/integratedarchitecture/resources3.html#enetpredict

EtherNet/IP Capacity Tool

It is a pretty handy tool for Logix systems.

mellis said:

First break for me would be I/O vs non-I/O. Your Ethernet/IP traffic on one network, everything else on the other network. I think I'd put the servo system on the I/O network.

Click to expand...

That is also how I would do it.

We separate our plant network connection from our IO network. This allows us to use fixed IP addressing on our own subnet without burdening IT. It divides the networks between theirs and ours. I recommend that you use a managed switch on your IO network.

One network should be able to handle all of your IO without even breaking a sweat.