plc network

Hi
I was hoping someone here could help me with a networking question. I have a customer that would like to connect all thier equipment on a network. They have several compact logix and one control logix as well as a few slc's. There are many hmi's and remote I/o modules as well. I would like to connect everything to one central plc for data collection. The problem is the ip addresses are all over the map and in not any particular order. Is there a way to have devices on different networks send and recieve data without changing all the ip addresses. For example...one machine has 12 ip addresses in one group (192.168.10.xx) and another has 8 (172.100.0.xx).

This is exactly what routers are built to do.

Does your client have an IT department that administers their enterprise network, or are they relying on you to sort out their various automation networks ?

A-B has some products like the NAT Appliance that might work for you, or you can choose an industrial router provider like Moxa or Cisco.

Start by putting yourself through a basic tutorial on IP subnetting and how routers and Network Address Translation work.

Gather as much information as you can on what devices are connected together using which IP network addresses.

Thank you Ken.
My customer has an "IT guy" but he is no help at all. I am not too familiar with networking but am actually looking forward to learning something on this job without losing too much money for my boss.
I was trying to connect through a gateway but not having much success.

Let's limit the discussion to "how do I connect an automation network to the enterprise network if the IP addresses are different.

For our purposes, the "Enterprise Network" has addresses 192.168.10.xxx, while you also have a machine system that's been installed with addresses 172.100.0.xxx. The machine system has a ControlLogix and you want to be able to download and go online with the ControlLogix.

One device you can use is a Network Address Translation (NAT) appliance. A-B makes one called the 9300-ENA.

That device is going to translate between enterprise network addresses and machine network addresses.

Say you set up a translation relationship between 192.168.10.50 and 172.100.0.4 (the address of the ControlLogix on the machine network).

When a frame comes into the 9300-ENA that's addressed to 192.168.10.50, it will repackage it and retransmit it to address 172.100.0.4, and then do the same to the reply.

The net effect is that PLCs and software on the Enterprise network now think the ControlLogix is at 192.168.10.50.

Now this isn't magic, and you can get confused. This is especially true if the networks aren't physically separated: you could end up talking to the ControlLogix at both addresses !

And you need to know your RSLinx really well; the auto-browsing features of RSLinx need special attention and careful configuration when you're using NAT and routers.

To clarify: I talked both about your IT department's "enterprise network" and then moved on to talking about an "enterprise network" that was really a way to connect the disparate little automation LANs.

This really is a "take a step back and figure out what you've got, then read up on the core technologies" sort of project.

You might find that it's best to go re-address a bunch of PLCs and HMIs and I/O devices, just to bring a little more order to the chaos.

Start by identifying what's physically connected together and what's logically grouped together, and start thinking about how you want those things to be interconnected.