RSLinx Light

Hello,

I am attempting to communicate to a ControlLogix PLC via Ethernet. The PLC is located behind a firewall (router) and I am attempting to configure an ethernet device driver in RSLinx Light in order to go online. I am able to log into the firewall and ping the PLC so I know I have communication. However I am unable to get an open connection. Does anyone have any idea what I am doing wrong?

Dan Kreiling

dksj67 said:

Hello,

I am attempting to communicate to a ControlLogix PLC via Ethernet. The PLC is located behind a firewall (router) and I am attempting to configure an ethernet device driver in RSLinx Light in order to go online. I am able to log into the firewall and ping the PLC so I know I have communication. However I am unable to get an open connection. Does anyone have any idea what I am doing wrong?

Dan Kreiling

Click to expand...

What's your PCs ip/
Must be in the same range and subnet as the PLC
Use something like xxx.xxx.xxx.245
usually IT depts reserve the above and don't use them.

What version of rSLinx?
The yellow mark means that Linx sees it but won't recognize it since it is unable to know what kind of device.
I'd upgrade the RSLinx version, itis free.
You can download from the AB site.
Hope this helps.

along with what was already mentioned the subnet also has to be the same yuo0 can shange this by going to the network icon goto properties\tcp IP most likely you are using DHCP click specify IP

Just went thru some of this with a ML1500 and all the add ons it took to accomplish what should have been simple. Maybe it is after you have done a hundred or so. The experience also made my yearly support fee worth the money. Can't help otherwise.

xxx.xxx.xxx.245

I would go further in your case set your network adaptor to 143.219.13.245

Just went thru some of this with a ML1500 and all the add ons it took to accomplish what should have been simple. Maybe it is after you have done a hundred or so. The experience also made my yearly support fee worth the money. Can't help otherwise.

this operation is usually simple provided you understand the IP rules. The most common mistake is not setting your network adaptor to a compatible range and subnet. Howver this becomes tricky if the IP and subnet is not known thankfully they include Boottp with RS linx but this only works if Boottp is enabled on the ethernet adaptor. Speaking of which the other possiblity is that your ethernet module may have lost its IP or subnet settings. If this is the case you may need to use the Boottp you do this by entering the MAC address of the ethernet module this should be written on the module. provided Boottp is enabled it will allow you to reassign the IP and subnet. The other method is to go through the processor channel connection methods then through the backplane to write to the ethernet module

Clarification

All,

I am trying to access the PLC from outside of the subnet. So setting my local IP address to the same settings wont help. My laptop IP address is assigned dynamically through DHCP. What gets me is that I am able to ping the PLC from outside of the subnet across the firewall but cant get RSLinx to communicate. My ultimate goal would be to be able to log into my corporate VPN from the Internet and access the PLC.

Dan Kreiling

One of the easiest ways to do this is to have RS logix on an interface PC with two network cards. You log into the interface PC with VPN or gotoassist then run RS logix from that PC to the PLC the other method would be to talk to the IT dept there and have the VPN server witht the copy of RS logix on it. Firewalls usually do not interfere with Pings the ping command works provided there is a connection path and tends to ignore firewalls. Most remote connections I've worked on usually have the first method of hookup I mentioned. Unfortunately the Dhcp makes the routing tricky your network administrator may be able to help if they are using manageable data switches he should be able to set up a routing table to route and allow the call. If its possible see if you can place the fixed IP of the PLC onto the VPN network which I'm assuming is the office network. for this you would need the assistance of your network administrator as he would have to ensure the DHCP does not attempt to change the fixed IP but this is can be done via the routing tables that they manage

When it first browses a network , the RSLinx Classic AB_ETH driver first attempts to connect using TCP Port 2222, the old A-B CSPv4 protocol port.

If the target device is not a PLC-5E or SLC-5/05, it supports only EtherNet/IP on TCP Port 44818 and will return a "port closed" response to RSLinx Classic when it requests a connection to Port 2222.

After three "port closed" responses, RSLinx Classic switches to Port 44818.

If you want to skip those Port 2222 requests, append ":EIP" to the end of the host address in the AB_ETH driver host list.

All this being said: you need Port 44818 open. PING proves basic connectivity, but you need to prove that Port 44818 is passing through the firewall. I like to also use TCPING to Port 44818 to prove out the firewall and be sure there's nothing preventing RSLinx Classic from connecting.

http://www.home-network-help.com/ip-forwarding.html

this guy is currently having similar probs there was a suggestion there that may apply the suggestion is linked above the thread is
http://www.plctalk.net/qanda/showthread.php?t=54145&goto=newpost