NET-ENI Message

Hi,
Is there anyone that can help me with a message instruction between two compact logic controllers. I have one compact L23E connected to our plant network and another L23E with a NET-ENI connected to the serial port. I am using a MSG instruction to read a block of 16 dint tags from the first PLC through the NET-ENI that is connected to the second plc.
I can get to the processor through RSlinx so I know the adapter is set up ok but can not get my message to read from the plc.
I do have several PLC / ENI adapters communicating on the same network but the other PLC's with ENI adapters are all SLC's.

Any help would be appreciated.
Thanks.........

You need to add the IP of the L23E that doesn't have the ENI to the message routing table of the ENI.

Why do you need to use the NET-ENI if both cpu's have on board Ethernet?

beethoven_ii said:

Why do you need to use the NET-ENI if both cpu's have on board Ethernet?

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I knew someone would ask that question. The reason is, I have several machines on a network so I can collect production data and put it on a spreadsheet. There are two machines made by the same company with identical IP addresses. Each machine has 7 compact logic plc's as well as remote I/O blocks and ethernet I/P valve banks, vision, etc.
Rather than attempting to change all the I/p addresses I figured it would be easier to use the net- eni on one of the plc's and all the data on this machine can be read from each plc and channeled through one plc on the system through the seral port via the net-eni. This way, the network on machine 1 is totally isolated from machine 2.

This might be a CIP connection resource problem, or a PLC/SLC Mapping problem, or a "Use CompactLogix Routing" feature problem, or just a simple CIP Tag Name syntax problem.

Because you can access the target controller using RSLinx Classic through the Net-ENI, I think it's unlikely to be an Autobaud problem or a BCC/CRC Error Checking problem.

Because the source controller is using its built-in Ethernet port, this isn't a routing table problem.

I am using a MSG instruction to read a block of 16 dint tags from the first PLC through the NET-ENI that is connected to the second plc.

Click to expand...

To confirm: the originating controller with the MSG instruction is connected to the network through its built-in Ethernet port, while the target controller is connected to the network through a 1761-NET-ENI.

Do you know which Series letter the Net-ENI is ? The Series A units and maybe some of the early Series B units could not accept this sort of message and you needed to have a Net-ENI on both ends.

Are you using PLCS/SLC style data table mapping, or ordinary CIP Data Table Read/Write commands ?

What is the error message you are getting on the MSG instruction ?

7 CompactLogix 1769-L23E PLC's

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all the data on this machine can be read from each plc and channeled through one plc on the system through the serial port via the net-eni.

Click to expand...

Now it sounds more and more like a CIP Connection capacity problem. You're dealing with the devices in the RA product line with the very lowest CIP Connection capacities.

Was it your intent to use the 1761-NET-ENI to connect to the enterprise network ?

If so, you might (might !) be able to get the other six CompactLogix to send their data to the serially-connected CompactLogix over their built-in Ethernet ports.

There's a much better way to do this: a 1:1 NAT device.

I recently employed this on a system similar to yours: each machine workcell had several ControlLogix, its own HMI, and I/O and drives on Ethernet. They were built as standalone cells by the same OEM, and had duplicate sets of IP addresses.

We even stuck with A-B hardware: we put a 9300-ENA Network Address Translation device on each system.

From the outside, each system looks like a different set of IP addresses on the enterprise network.

From the inside, they all look identical.

Thank you for you replies.
The ENI is a series D and I am using a CIP read and the error I get is IOI syntax error. I did try the 1:1 NAT device but the problem I had with it was I could not overlap addresses. The first machine uses a class B network with each cell using identical addresses except the third number of the address is changed on each cell. (Cell 10 = 172.16.10.1, Cell 20 = 172.16.20.1, etc.). Subnet mask is 255.255.0.0. My industrial network for the equipment uses 172.16.1.xxx . for machines in room 1 and 172.16.2.xxx for machines in room 2 etc. Subnet mask is 255.255.0.0. If I set my local address using 172.16.x.x and my uplink address must also be 172.16.x.x using a mask of 255.255.0.0, I get an error telling me the addresses can not overlap. Grrrrr.....
Anyway, I had a lot of trouble trying to get it to work and thought the ENI would be another solution. I have run out of time and money and need to get some data real soon.......

My CIP read route on the PLC without ENI is set at Local ENB , 2, 172.16.2.3 which is the address of the ENI on the PLC I am trying to read from. I can't understand why it will not work but I must be missing something.

Try adding hops to the end of the CIP Path.

First, try "3, 1". I read in the Knowledgebase that's CompactLogix and ENI specific.

If that doesn't work, try "1, 0". That's the default "right to the controller" path for old ControlLogix.

Be sure the tag you're trying to read is Controller-scope (not Program-scope) and that you have the datatypes and spelling exactly right.

Thanks Ken
I will give this a shot on Monday......

shawn_75 said:

You need to add the IP of the L23E that doesn't have the ENI to the message routing table of the ENI.

Click to expand...

Thanks Shawn.
I did add the IP to the routing table but still won't work.

Thank you Ken
3, 1 did the trick.........