CompactLogix 1769-L32E

Hi ,
I would like to add a second Ethernet card to a CompactLogix PLC that already has a 1769-L32E processor (build in Ethernet Port).

I did not found any Additionnal Ethernet cards in AB Web Site.
Does it exist cards from other manufacturer?

Alain

If you really need multiple isolated Ethernet interfaces to the same Logix controller, you need to use the 1756-series ControlLogix with 1756-ENBT modules, or the 1768-L43/L45 CompactLogix with 1768-ENBT modules.

What is your reason for wanting/needing two EtherNet/IP interfaces on a CompactLogix controller ?

We typically do it to separate the Ethernet IP I/O racks from Ethernet to the HMI stations. They are separated to lower ethernet traffic.

I've only run multiple ethernet cards on the 1756 platform though--sorry I can't help with the CompactLogix.

To expand a bit on what Eddie said, with the 1768-L43/45 processors, there is another buss where communications cards can be added to the left of the processor. I believe at this point, there can be a maximum of 2 communications cards on the 1768 buss (left side of the processor), but they are currently working on expanding that to 4 cards.

I did some price comparizon (1769-L32E VS L43) there is a big gap. L43 is a lot more expensive.
Also I'll need to add two 1769-ENBT Cards in order to get two Ethernet network.
Is it possible to add the 1769-ENBT card to 1769-L32E processor?

That's a negative Alan. 1769-ENBT is not a part they make, it's 1768-ENBT. That goes with the L40 series processors. I believe your only other option would be to go with a net-eni module connected to the serial port.

Or go to Control Logix.

No, it is not possible to add A-B Ethernet modules to the 1769-L32E or 1769-L35E.

1768-ENBT modules may only be added to the 1769-L43 and 1769-L45 controllers through their "left side bus".

If you need multiple independent Ethernet interfaces, you need to buy a modular controller.

What is your reason for desiring an independent Ethernet port on the CompactLogix 1769-L32E ?

The actual Ethernet port is used to control remote I/O .
I would like to add an extra card to connect that PLC to an existing Ethernet network already connected to multiple Contrologix PLC (for data collection usage).

You could use a 1761-NET-ENI.

You don't need another independent Ethernet port; you just need a way to isolate your I/O network from the information network and providing a translation between network addresses.

What you need is an ordinary Ethernet router.

Even though I prefer DIN-rail-mounted gear with 24VDC power, you really can't beat the good old Linksys BEFSR41 router for this kind of application.

The only thing you have to do is configure Port Forwarding so that any incoming connections to the WAN side of the BEFSR41 on TCP Port 2222 or Port 44818 are forwarded to your CompactLogix IP address on the LAN side.

The multicast I/O traffic remains on the LAN side, and the CompactLogix appears as though it was a different IP address on the WAN side.

Hobby time

I discussed this with another engineer and he said he had tried and then removed a home router in this kind of application because it would not handle all the UDP multicast traffic on the LAN side. Installing a suitable managed switch that will keep UDP traffic away from the router port would do the job, but now I'm curious about exactly how much UDP multicast traffic will blind or jam a simple router, or if there are settings that will allow it to perform in a satisfactory manner.

While I still don't recommend consumer-grade hardware for industrial networking, I figured I'd put my money where my mouth is and hook up precisely this device in a similar application.

On Friday afternoon I scored big at the local Goodwill thrift store; a Linksys BEFSR41 v3 (the ones with the Cisco label on them) and the appropriate 9VAC power adapter for $12.00, and a rare functional Netgear DS104 hub and power supply for the same price. The hard part was finding and untangling the power supply cables in a tub of Medusan properties.

The BEFSR41 v3 turned out to have an intermittent power supply connection and was locked up, network wise. No wonder, since it was in a stack of routers at Goodwill. I performed a hard reset and use dentist's tools to firm up the power supply connection and now it is up and running.

At the office I have a PowerFlex 70, a PowerFlex 40, some FLEX I/O and a couple of ControlLogix with 1756-ENBT modules. This should be enough to generate a few thousand packets per second of EtherNet/IP traffic to see how the Linksys BEFSR41 v3 handles it, and how the browsing and communications from the WAN side can be accomplished.

Ken - I'm curious to hear how it goes.

Ken
It is intresting if it will work with v3:
3 years ago I did same experiment: I took from home BEFSR41 v1 - very first revision that was released in late 90s. It was in perfect working condition: I just replaced it with wireless version to get laptop connection.
I connected it to my test bed that has 40+ devices and multple switches.
LAN side was ok, but for some reason I could not get WAN side to work and internal webserver was not accessable from LAN or WAN.
Multiple resets did not help so I took it home hoping it will work as it did before - no luck - WAN side and router portion was dead. It is dead since.
Looks like heavy multicast traffic killed it, still not sure how.

So it's intresting if later version will work.

Gentlemen
I have no detailed information to offer other than, I have tried every imaginable conection scheme using a Linksys WRTG54S as a wireless access point.
It is a new unit a little over 3 months old. It works like a champ at home and at the office. It absolutely slows to a crawl when connected to a "control" network with UDP multicast traffic on it. The webserver even stalls out. I think the router's little cpu just gets totally overwhelmed. As soon as you unplug it from the UDP traffic boom the web server works and it behaves normally. Controls traffic is NOT a job for an off the shelf router. (at least not a linksys anyway)

I have since started using a linksys WAP54G wireless access point instead. It works very well with absolutely no issues. It however does not try and route, manage, or block any traffic.

RSL

RSL

Did you actually try hard resets (as opposed to just pressing the reset button) or firmware upgrades?

I wouldn't expect the router to pass multicast packets (TCP or UDP), but I've been hesitant to pipe up because I'm not totally sure in the case of a Linksys router. Typically, routers segment broadcast domains, by not passing broadcast and multicast packets. If they are "multicast capable" then they can be enabled to pass multicast traffic with inter-router protocols like DVMRP/PIM (in the Cisco world, at least). My more expensive and modern home D-Link gaming router appears to have features to allow some level of support. When thinking about this consider that we're talking about Layer 3, and there are things that can be done at Layer 2 (inter VLAN routing/bridging) that might be seamless.

Contr_Conn said:

Ken
It is intresting if it will work with v3:
3 years ago I did same experiment: I took from home BEFSR41 v1 - very first revision that was released in late 90s. It was in perfect working condition: I just replaced it with wireless version to get laptop connection.
I connected it to my test bed that has 40+ devices and multple switches.
LAN side was ok, but for some reason I could not get WAN side to work and internal webserver was not accessable from LAN or WAN.
Multiple resets did not help so I took it home hoping it will work as it did before - no luck - WAN side and router portion was dead. It is dead since.
Looks like heavy multicast traffic killed it, still not sure how.

So it's intresting if later version will work.

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