CompactLogix controller with Two Ethernet Ports?

sanger

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Join Date
Nov 2005
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Toronto
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Do any CompactLogix controllers exist with dual Ethernet built in or the ability to add a second Ethernet port as an add-on?
 
The newest series has dual Ethernet ports. They also have a USB port for programming.

Here's their selection guide.

Edited to add:
Note that, as far as I can tell, the CPU does not support multiple IP addresses. It looks like the L4x processors support a 1769-ENBT module. Without digging in too much detail, the selection guide appears to indicate that the L4x do not have the on board Ethernet port(s).
 
Last edited:
As joseph_e2 indicated the CPX with two ports only has one IP address. The dual ports are a built-in mini-switch intended to support the DLR (??dual loop redundant??) topology.

To the best of my knowledge, if you need two IP addresses and you want to stick with CPX you need to go with an L4X processor and use two 1768-ENBT modules.

Keith
 
I replaced a L35 with a L43 to accomplish just this.
The two ethernet cards mentioned above attach to the 1768 buss left of the processor. You will need a new power supply also, which attaches left of the ethernet modules. Works great to keep a local ENET/IP Control system seperate from the LAN and still have remote access to the controller.
 
We had to switch from an 3x to a 4x CLX processor for just that reason. Due to poor network design (or lack thereof) we'd have occasional outages which would disrupt control traffic. Isolating the two networks was our 'short term' answer untill IT could sort the network out. The best solution may be, however, a high level managed switch that supports VLANS and such (this is actually Rockwells recommendations). Properly managed, this will give you the greatest flexibility. The problem with two seperate networks is that there isn't anyway to bridge between the two ethernet cards efectively isolating you from any remote diagnostics.
 
The problem with two seperate networks is that there isn't anyway to bridge between the two ethernet cards efectively isolating you from any remote diagnostics.

That's not 100% correct. With a layer 2 switch and VLAN's that are not in the same subnet this statement is true but if you have a layer 3 switch then you can have traffic from you laptop reach everthing on the plc side for diagnostic purposes such as pinging devices and the webpages of the plc's and drives. You can remote control HMI's this way also but with the routing setup correctly these devices will only pass traffic to you laptops or engineering stations and not the rest of the network.

Also you never want automation devices on a corporate network even if IT can "work it out" and make it work. This is by default a very bad practice and will cause you issues. Not a question of if it will cause issues but when.
 
That's not 100% correct. With a layer 2 switch and VLAN's that are not in the same subnet this statement is true but if you have a layer 3 switch then you can have traffic from you laptop reach everthing on the plc side for diagnostic purposes such as pinging devices and the webpages of the plc's and drives. You can remote control HMI's this way also but with the routing setup correctly these devices will only pass traffic to you laptops or engineering stations and not the rest of the network.

My point was that if you have two NIC cards in a CompacLogix you can not bridge between the two networks. The preferred method is using a Layer 3 switch.

Also you never want automation devices on a corporate network even if IT can "work it out" and make it work. This is by default a very bad practice and will cause you issues. Not a question of if it will cause issues but when.

This is contrary to Rockwells recommendations regarding EthernetIP Properly managed with VLAN's and such.
 
My point was that if you have two NIC cards in a CompacLogix you can not bridge between the two networks. The preferred method is using a Layer 3 switch..

Sure you can. With a layer 2 or 3 switch depending and by varios other methods. Not a good practice but canbe done.



This is contrary to Rockwells recommendations regarding EthernetIP Properly managed with VLAN's and such.

Rockwell has never advocated placing your automation devices on the same logical network as your corporate network. We are talking logical networks here not physical. Physical can be the smame or seperate your choice. IMO the physical needs to be seperate and only connected at one specific point. This is a common best pactice in any IT enviroment. Isolation is a good thing but it needs to be controlled isolation.
 
If you know of a way to bridge between two CompactLogix Ethernet cards without physically attaching the two networks please share.

Rockwell has never advocated placing your automation devices on the same logical network as your corporate network.

That's what I just said.
 
There is good justification for having two IP addresses on a PLC.
Yes, PLC should not be on the corporate network. We have a business (corporate) network, and a production network - completely isolated.

We like to have the PLC, HMIs, & Drives on the production network AND THEN all the remote I/O, intelligent OLs and such on the local 192.168.1.X so we can use the thumbwheel to set the address on the IO. This easy allows replacement for IO components WITHOUT the use of Rockwells wonderful BOOT-P at 2am.

This allows us to login into the PLC & Drive for programming & troubleshooting,
It also gives the PLC better access time to the IO since the multiple drives and HMI are not hogging the bandwidth. Even if you use an EXPENSIVE Level 3 switch all traffic is still going through on cable into one port. But I do like the idea of being able to ping the components on the local subnet like you can do with a Level 3 switch like "The PLC Kid" does.
 
FYI - I did not check the date on the last post. So this is probably a dead issue.
Not sure why I pop-up on new post for me. Sorry to waste other peoples time.
 

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