1783-natr

Can anyone tell me what I am doing wrong with this layout. I am trying to set this up on my desk and make it work before I try a more complex network.
The picture attached is how I am set up and I can't get any communication between the PC and the PLC.

Thanks

Yes, you have mapped your PLC to the same address as your laptop is using.

Change the NAT entry for the PLC to something like:

Private: leave same
Public: 172.29.73.unused address

I think that'll do it.

Also, you don't need to have your laptop gateway set for the public port address because the PLC has been NAT'd to an address in your local network.

To be a bit more clear.....this NAT does not require you to set up the translation in both directions like some devices would have you do. So you only need to translate your device from the private side to the public side. The translations you set up must have unused address on the private side else you will have IP conflicts for those addresses.

Once you translate the PLC to an address on the public side, your laptop won't know the difference....it will treat that address just like any other address in it's local network.

Give that a try.

scarince said:

The translations you set up must have unused address on the private side else you will have IP conflicts for those addresses.

Click to expand...

Arrgh....I made a typo here.....this should say "unused address on the PUBLIC side".

Sorry for the potentially confusing mistake.

B.

Alright I'll try that. Thanks for the help

Use the private IP address of the NATR as the gateway address of all users on the private side.

So now I have changed the NAT translation IP address for the public port to 172.29.73.32 and I can only see the public side of the switch on RSlinx. I still can't see the ENBT module and I cant ping its IP address of 130.90.167.171?

Have you set a NAT rule for your ENBT?
Did you set the gateway address of the ENBT to the NATR Private IP address?

The GW on the ControlLogix needs to be set to the private IP of the NATR module.

scarince said:

yes, you have mapped your plc to the same address as your laptop is using.
...
Also, you don't need to have your laptop gateway set for the public port address because the plc has been nat'd to an address in your local network.
...
Give that a try.

Click to expand...

+1

Yes I am set up just like the diagram shows except I changed the NAT rule public IP to 172.29.73.32. The private address of the rule is the ENBT address and the gateway of the ENBT is the address of the private port.

J2009 said:

So now I have changed the NAT translation IP address for the public port to 172.29.73.32 and I can only see the public side of the switch on RSlinx. I still can't see the ENBT module and I cant ping its IP address of 130.90.167.171?

Click to expand...

Okay, a few things:

You won't be able to ping the private address from the public side, you can only ping the PLC's translated address, the translation that you put in the NAT table.

Also, don't think of this as a "translation IP address for the public port.....". You are setting up a translation to make the private devices public. That is all you are doing.

Also, be aware that when you are on the public side with your laptop running Linx, you have to use the Ethernet driver, not the Ethernet/IP driver. So you will need to configure the Ethernet driver to have your PLC's Public IP address. You should be able to ping that public address and get a response.

And as mentioned above, the PLC gateway address must be the address of your private port. If the layout you sent is correct then it looks like you have this right.

So, with the changes I mentioned yesterday you should be able to plug your laptop in on the public side and ping the plc.

If you can't then plug your laptop into the other private port, change your adapter settings accordingly, and confirm you can ping the plc's private address on the private side.

b.

J2009 said:

Yes I am set up just like the diagram shows except I changed the NAT rule public IP to 172.29.73.32. The private address of the rule is the ENBT address and the gateway of the ENBT is the address of the private port.

Click to expand...

You should just have ONE entry in the NAT table!

Based on your diagram, the entry will be:

Private:130.90.168.171
Public:172.29.73.32

That's it! No other entry based on your diagram.

Give that a try.

Just curious, what does this NAT device even do? I just plug straight into the PLC from the laptop, not going through any devices. Also, how did you assign 2 IP addresses to the PLC, one looks like a private IP and one public? This is used for additional security or something?

NAT = Network Address Translation. Allows devices on different networks, public and private, to talk as if on a common address scheme. A good example is when a company has two or more isolated machine cells with identical address (machine builders like to do this) and they want to interface with all of them through a single SCADA system. NATs between each cell and the SCADA can accomplish this.

Okay, a few things:

Also, be aware that when you are on the public side with your laptop running Linx, you have to use the Ethernet driver, not the Ethernet/IP driver.

Click to expand...

Scarince

Could you clarify differences between Ethernet driver vs. Ethernet/IP driver and reason to use Ethernet driver.

Regards:
Sydney