Network setup with 1783-NATR

Hi everybody,

I have a standard system with a PLC (1769-L16ER-BB1B) and a HMI (Panelview plus 7) that I want to integrate in a plant network.
The customer wants to exchange a couple of bits using produce and consume so I integrated everything already in our software.
I prepared and tested everything and it worked just fine.

My test setup was a our usual system (1769-L16ER-BB1B +Panelview plus 7) connected to another AB PLC to communicate with. Everything was connected as 1 network (see picture test setup).
Normally when we integrate something like this in a bigger network we just ask for 2 IP adresses for the PLC and HMI in the customer's network.

In this case the customer can only asign 1 IP adress (102.2.245.10) for our system to comunicate with their system (102.2.245.81).
I've been in touch with Rockwell Belgium and they told me I need a 1783-NATR to achieve this.

My question now is how do I set this up ?
I'm guessing the IP adress of the public IP adress will be the one that got assigned to us (102.2.245.10) ?
But what do I put in the translations as an public adress for my PLC with internal adress 192.168.16.98 ? (see picture actual setup)

I hope I can get some help this way, I'm just taking my first steps into AB programming.

Thanks a lot in advance

Pay attention to the very end, there is a note about the gateway on the local side.

https://www.youtube.com/watch?v=eZtWzdPeVOg

dmroeder said:

Pay attention to the very end, there is a note about the gateway on the local side.

https://www.youtube.com/watch?v=eZtWzdPeVOg

Click to expand...

Already saw this video this afternoon
Thanks to this I was finally able to see everything in RSlinx.

But I'm still confused on what the public adress and what the translation rule should be for my PLC.

Michiel said:

Already saw this video this afternoon
But I'm still confused on what the public adress and what the translation rule should be for my PLC.

Click to expand...

ASSUMING all netmasks are 255.255.255.0:


The rules are

• the first three octets (e.g. 192, 168, and 123, of 192.168.123.x) cannot be the same for the public and private addresses of the 1783-NATR
• the first three octets of all devices on the private side of the 1783-NATR must be the same as the first three octets of the private address assigned to the 1783-NATR
• the last octet (.x above) of the private addresses cannot be the same as the last octet of the private address of the 1783-NATR, nor can it be the same as the last octet of the private adress of any other private device
• the last octet of the public addresses for a private device cannot be the same as the last octet of the public address of the 1783-NATR, nor can it be the same as the last octet of any public address of any other private device
  • N.B. this rule will probably be enforced by the 1783-NATR
• the last octet cannot be 255 for any address, public or private

Furthermore,

• As noted above, the public IP address for the private PLC will have the same first three octets as the public IP address of the 1783-NATR.
  • Only the 1783-NATR knows about the public addresses
  • The private PLC itself only knows its private IP address
    • It has absolutely no idea about its public IP address.
• Example:
  • Public IP address of 1783-NATR is 192.168.123.1
    • All public addresses will be 192.168.123.xpublic for the private PLCs
  • Private IP oaddress of 1783-NATR is 192.168.231.231
    • All devices on the private network will have addresses of 192.168.231.xprivate
  • The mapping from public address 192.168.123.xpublic to 192.168.231.xprivate will be done in the 1783-NATR only.
  • .xprivate and .xpublic may be the same, or they may be different; it doesn't matter.

Thanks for the information, all makes sense.

Just one thing I'm still confused about...
Do I have to assign the IP adress we got from our customer (102.2.245.10) to the public port of the NATR or does this have to be a public translation of my Private PLC's IP adress ?
Keeping in mind that we can only use 1 IP adress in the public network

picture of network

Michiel said:

Thanks for the information, all makes sense.

Just one thing I'm still confused about...
Do I have to assign the IP adress we got from our customer (102.2.245.10) to the public port of the NATR or does this have to be a public translation of my Private PLC's IP adress ?
Keeping in mind that we can only use 1 IP adress in the public network

Click to expand...

ooh, the NATR does not solve the problem: even with the NATR, the new hardware is still using up at least two addresses on the public LAN.

Can you do this? I have no idea if CompactLogix can handle multiple Ethernet interfaces; if not, can the HMI communicate with summat else serial?

drbitboy said:

ooh, the NATR does not solve the problem: even with the NATR, the new hardware is still using up at least two addresses on the public LAN.

Click to expand...

Exactly what I was afraid of

Is the customer's device pulling from your device, or is your device pushing (initiating) the connection?

drbitboy said:

Can you do this? I have no idea if CompactLogix can handle multiple Ethernet interfaces; if not, can the HMI communicate with summat else serial?

Click to expand...

This is what the customer wants, but it is't not possible with our actual PLC (compactlogix, 1769-L16ER-BB1B). Are there any other modules that can be used instead of changing the PLC ?

drbitboy said:

Is the customer's device pulling from your device, or is your device pushing (initiating) the connection?

Click to expand...

Both devices are consuming and producing so I guess the connection goes both ways ?

Michiel said:

This is what the customer wants, but it is't not possible with our actual PLC (compactlogix, 1769-L16ER-BB1B). Are there any other modules that can be used instead of changing the PLC ?

Click to expand...

can you add ethernet card to the 1769?


Also, you might be able to do a standard soho-network type of NAT to hide your HMI/PLC combination behind a regular old router, and port-forward the PLC E/IP port(s?) to the router and the customer connects to that.

http://www.plctalk.net/qanda/showthread.php?t=122267




That may be close to what you are trying to do.


You should be able to test that on your own.

drbitboy said:

http://www.plctalk.net/qanda/showthread.php?t=122267




That may be close to what you are trying to do.


You should be able to test that on your own.

Click to expand...

Thanks a lot, I will surely take a look into this.
On the other hand I'll also ask our customer if we can get a second address for our HMI in their network.