Multiple Micrologix behind a router

Russff

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Mar 2006
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A customer has multiple AB Micrologix 1400's on an ethernet network behind a router. I need to access each of them remotely via the internet via RSLinx Lite and RSLogix 500 for programming.

I looked at an AB tech note which says to use "Remote Devices Via RSLinx Gateway" driver in RSLinx, but I don't exactly get it. So in this driver, I only need to enter the public IP of the router?

What needs to be setup in the router (it's the customer's router, so I don't know what it is)? I'm not sure exactly what the RSLinx Gateway driver does, does it just send a broadcast to port 44818 at the public IP address? So in the router, port 44818 needs to be rebroadcast out to the local subnet?
 
Are you one site? Or are you looking to access them remotely?

If you are on site then it is really easy. Just plug into the router and set up your computer with the proper IP address for the network. You may need to get the IT guy to turn on a port for you and give you a IP that you can use.

If you are remote, then you will need the IT guy to set up VPN access for you. Then you will have to download a VPN client. Once you have that you can run the client and enter your user name and password. You will be connected to their network just like you are on site.

I do this for several customers and it is a great way to fix small issues.
 
...
If you are remote, then you will need the IT guy to set up VPN access for you. Then you will have to download a VPN client. Once you have that you can run the client and enter your user name and password. You will be connected to their network just like you are on site....

Is the VPN client similar to a virtual machine?
Do you have to install RSLogix 500 on the VPN Client?
 
Is the VPN client similar to a virtual machine?
Do you have to install RSLogix 500 on the VPN Client?

no, a vpn client is just a software that you install which will connect your pc into the remote network, essentially making it like your pc is plugged directly into the network.
 
VPN systems are Virtual Private Networks, its a private/encrypted tunnel connection back to the host network. As far as MicroLogix software will be concerned, you're plugged into the same network as the PLCs.. supposing the Router they have is VPN capable. If its not and only has VPN passthrough which is typical of cheaper ones, you won't be able to do this without a VPN host behind the router.
 
Bullzi...it would be remote access via the internet from my office. These PLC's are behind a router at the customer's site. I'm not sure what router the customer is using, if it can handle VPN or not. Some places just use their internet provider's router, which is pretty basic and does not handle VPN (as Nova5 mentioned), so it can only handle port forwardings. That's why I was looking into the "Remote Devices Via RSLinx Gateway" RSLinx driver, since it doesn't require VPN, just port forwarding (I think, I'm not sure how to tell the customer to setup his router for this driver, that's what my question is about). If their router can do VPN, great, if not, I need this other method available as plan B.
 
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I think the remote devices via rslinx gateway would only be applicable if they already had rslinx running on a pc behind the router. I may be wrong though.
 
Remote Devices via RSLinx Gateway are accessible only through RSLinx Gateway. Gateway acts as a router. You connect to Gateway, it routes you over to the PLC. That's turns into a license issue.

A lot of places tend to put their automation network on their enterprise network (same physical and logical networks). Others separate them out (the automation components on a different physical network.) In these cases you would only need VPN connection to whatever network the PLCs are on (see the top picture in the list with the 10-57-58 timestamp).

Ours is a bit different. Each cell is on it's own physical/logical network. A PC router is on each line to connect to the enterprise network. In this instance, every router needs to run RSLinx Gateway to provide connectivity outside of it's "local network". A VPN connection is still needed to access from outside the enterprise network (see the other pic).

2015-01-22_10-57-58.png 2015-01-22_10-56-57.png
 
With proper port forwarding, you don't need a gateway. I'm not familiar with what ports RSLinx/RSLogix uses, or if you can change what ports it uses by default, so it may not even be possible with simple port forwarding.

If, for example, RSLinx/RSLogix needed ports 123 and 456 to communicate with a PLC/HMI, you would need to set the router up to forward ports of your choosing to each PLC's IP address's port 123 and port 456 (I usually go with 1123, 2123, 3123, 4123, etc to make it easy, but their IT may dictate ports to use). Then you would need to tell RSLinx/RSLogix to connect to the router's IP address at ports 1123 and 1456 (or whatever ports you picked) for PLC1 and 2123/2456 for PLC2, etc. Again, I don't actually know what ports are needed nor how to change which ports RSLinx/RSLogix are trying to connect to.
 
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An example with B&R, you can get away with just port 11159 for communication to the PLC, but you could also add in port 5900 to get access to the VNC server for the HMI and other standard ports, like FTP on port 21.

I would configure the router to forward external port 11159 to internal port 11159 on the first PLC and port 21159 to port 11159 on the second PLC and similar with ports 15900 and 25900 going to 5900 on the two PLCs. Then, from the internet, I connect to the router's WAN IP address on port 21159 (configured in the Online settings in Automation Studio) and I would have connection to the second PLC and I could connect to port 25900 with RealVNC to pull up the HMI.

Or you could use an e WON and not have to screw around with your customer's router.
 
With proper port forwarding, you don't need a gateway. I'm not familiar with what ports RSLinx/RSLogix uses, or if you can change what ports it uses by default, so it may not even be possible with simple port forwarding.

If, for example, RSLinx/RSLogix needed ports 123 and 456 to communicate with a PLC/HMI, you would need to set the router up to forward ports of your choosing to each PLC's IP address's port 123 and port 456 (I usually go with 1123, 2123, 3123, 4123, etc to make it easy, but their IT may dictate ports to use). Then you would need to tell RSLinx/RSLogix to connect to the router's IP address at ports 1123 and 1456 (or whatever ports you picked) for PLC1 and 2123/2456 for PLC2, etc. Again, I don't actually know what ports are needed nor how to change which ports RSLinx/RSLogix are trying to connect to.

Problem with that, not all routers allow you to alter the ports like that. He'd need to ensure the router can take Port 1123 and direct it to not only the PLC's IP but CHANGE the port request to 123. To make it work easier, replacing the router with a VPN Router (NetGear FVS318G is what I have used) which will bring him into that local network group as if he was there will be the simplest way and won't require any trickery that could be problematic.
 
Then there's the problem with security. Port Forwarding doesn't have any. You would just be hoping that no one else with the software is poking around looking for openings.

VPN has provisions for security.
 
Im not sure that you can tell rslinx to use a certain port for a certain device. I think with rslinx the default ports used for comms are fixed. So if you had multiple plcs you couldnt use port forwarding unless you had them change the port forwarding rules for each plc individually.
 
Im not sure that you can tell rslinx to use a certain port for a certain device. I think with rslinx the default ports used for comms are fixed. So if you had multiple plcs you couldnt use port forwarding unless you had them change the port forwarding rules for each plc individually.
Exactly. And if you have a project spread out over more than one PLC, you're pretty well hosed.
 

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