Multiple Micrologix behind a router

[Russff]

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.

You can't, RSLinx uses port 44818 and it cannot be changed. AB tech support confirmed this, otherwise port forwarding would have been the easy way to go with each PLC using its own port.

VPN does provide security, but my needs are only to connect to a PLC to do some troubleshooting or reprogramming, so I would be connected for a short period of time. If I had some scada polling the PLC continuously, then security would be an issue.

So I'm still not sure if that "Remote Devices via RSLinx Gateway" driver requires RSLinx Gateway on the customers network. AB tech note 66666 says nothing about needing anything on the customer's end. That tech note closely describes my setup (but with Micrologix, not 5/05s).

 

[JordanCClark]

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.

If they can provide you with a VPN connection to the PLCs, then you don't need Gateway. Security considerations aside, VPN will also provide you with an IP that is on their subnet. You won't need to set anything else up.

It's when you have a physical or logical PLC network that is separate from their 'network at large', then you need Gateway to bridge and route between the two networks.

 

[Russff]

If they can provide you with a VPN connection to the PLCs, then you don't need Gateway. Security considerations aside, VPN will also provide you with an IP that is on their subnet. You won't need to set anything else up.

I agree VPN would be best, but I'm not sure they have that ability, so I need a backup plan in case they don't have VPN. There is no computer on the PLC network, just the four Micrologix. I need to be able to access each of them remotely from my office via the internet.

 

[diat150]

you should look at some type of vpn appliance that can be installed on their network, like the e w o n.

 

[Russff]

you should look at some type of vpn appliance that can be installed on their network, like the e w o n.

This wasn't that big a job where we can bury a $2K VPN device into the project cost. The customer won't pay for it, since they have no use for it, so it would be up to us. The RSLinx settings seem to be the way to do this, if I could figure out how to do it.

 

[Sourcejinn]

Unless you Put in a third party Kepware OPC driver and Middle tier OPC Server then just work off the data Served from that..

 

[diat150]

This wasn't that big a job where we can bury a $2K VPN device into the project cost. The customer won't pay for it, since they have no use for it, so it would be up to us. The RSLinx settings seem to be the way to do this, if I could figure out how to do it.

then there is not much else anyone can do to help you. you will either have to get them to setup a vpn on their existing router, port forward an individual plc one at a time, purchase a vpn appliance, or setup a pc running rslinx gateway on the local network.

 

[JordanCClark]

And, there are certainly other, sub-$2K VPN options out there. Heck, some are sub-$200...

People who say they have no need for VPN, are likely ones who haven't used it...

 

[blackandredwarrior]

We did a PLC project automating a cold storage that's an 8 hour drive away. I've tweaked things for two years as needed over a VPN. They just used a SonicWall TZ-Something (200 class, little small thing, maybe $500). Nothing special. They can skip the VPN, but they need to be prepared to pay for the service call if need be. I've gone in probably a dozen times and none of it would have been covered under warranty. 7 hour drive each way at $65/hr. Plus hotel over night.

 

[Sourcejinn]

Just a general question. what HMI / PLC are you using is it Allen-Bradley, CL or SLC RSView32, ME/SE, ? is it all a Connectivity problem between PLC's .....

 

[JordanCClark]

Just a general question. what HMI / PLC are you using is it Allen-Bradley, CL or SLC RSView32, ME/SE, ? is it all a Connectivity problem between PLC's .....

Did you read the original post?

 

[Russff]

then there is not much else anyone can do to help you. you will either have to get them to setup a vpn on their existing router, port forward an individual plc one at a time, purchase a vpn appliance, or setup a pc running rslinx gateway on the local network.

I thought there was a way to do this without a VPN, using port forwarding. Yes, it's not secure, but for our needs (reprogramming and troubleshooting), it would have been sufficient.

If there truly is no way to do this without VPN (or a computer on the PLC network running Gateway), then I can stop looking and have more motivation to convince our customer to use a router that has VPN.

Thanks for the suggestions. Even though I didn't get the answer I was after, I learned a few things in the process.

 

[diat150]

I thought there was a way to do this without a VPN, using port forwarding. Yes, it's not secure, but for our needs (reprogramming and troubleshooting), it would have been sufficient.

If there truly is no way to do this without VPN (or a computer on the PLC network running Gateway), then I can stop looking and have more motivation to convince our customer to use a router that has VPN.

Thanks for the suggestions. Even though I didn't get the answer I was after, I learned a few things in the process.

there is, but you can only do one plc at a time. also, just because it fits your needs doesnt mean that its ok to do it. depending on this system, you could have someone destroy equipment or even hurt someone if someone snoops around and gets access to the plc's. at that point, a $500 dollar router doesnt sound like much IMHO.

dont shoot the messenger!

 

[Russff]

there is, but you can only do one plc at a time.

I am going the VPN route, but just out of curiosity in case this may help on another job, what is the other way? I know I can forward port 44818 (which is not changeable in RSLinx) to a specific PLC, but without changing the port forwarding setup in the router each time I need to access a different PLC, how would you do it?

 

[JasonSelf]

I have been putting the **** Cozy (****.com) on all of my machines. it is a cloud based VPN purpose built for this very application, that does not allow upstream access to the IT network and requires no forwarding etc. They aren't inexpensive (almost $800) but they have paid for themselves wherever I have installed them. Spectrum has a competitor but it has an ongoing fee for each install, **** does not.