RSLinx, can ping but not connect

[scottmurphy]

I have VPN access to a customer site, and have had connections working previously, but now I cannot connect to the PLC. I mistakinly deleted the previous found nodes from the ETHIP driver, but could still connect.

I can ping the PLC, and when I run the Factory Talk application in test mode, I can read the live values from the PLC, but RSLinx does not find any of the nodes sitting on this network, which is, of course, preventing me from going online to the PLC.

I am trying to set this up on a new PC, but am having the same problem, I can ping the devices on the network, but not get online to the PLC.

Is there something that I need to set, to allow RSLinx to browse these nodes?

The thing that I am finding odd, is that I can see the nodes via RSLinx Enterprise in FT, but not RSLinx classic?

[Myles]

depending on the driver you use in RSLinx you need to right click on the word ethernet, select properties and input the IP Addresses you want to browse.

cheers

[scottmurphy]

depending on the driver you use in RSLinx you need to right click on the word ethernet, select properties and input the IP Addresses you want to browse.

I am using 2.51.00 (CPR7).

Odd thing is, I am currently updating the FT application over the VPN at the moment, is slower than if I was onsite, obviously, but is working nonetheless.

Must be something obvious? I have tried adjusting the CIP settings etc, but no joy, is there anything else that I could try?

[Ken Roach]

I think what you're seeing has to do with the way the RSLinx Classic drivers browse for the first time.

The "EtherNet/IP" driver performs a broadcast with the CIP "List Indentity" service, to which every EtherNet/IP device on the subnet that received the broadcast replies with its identity information (which is used to build the graphical icon array in RSWho). Once the devices have been discovered, RSLinx connects to them each subsequent time on TCP Port 44818.

This driver's browse only sometimes works with VPN circuits because many VPNs don't propagate broadcast packets. You might be able to get it to work by designating the VPN network instead of the local LAN when you create the driver.

The "Ethernet Devices" driver also can get blocked by VPN routers because it works both with classic A-B Ethernet devices (TCP Port 2222) and with EtherNet/IP devices (TCP Port 44818). The RSWho browse with the Ethernet Devices driver must see three "Port Closed" responses on Port 2222 before it tries Port 44818. If the VPN circuit doesn't pass all three Port Closed responses from the device (some VPNs interpret these as port scan attacks) then the driver doesn't switch to Port 44818.

In recent versions of RSLinx Classic, you can add ":EIP" to the end of the IP addresses you list in the Ethernet Devices driver configuration to skip the Port 2222 attempts.

Also I noticed in RSLinx 2.54 that when I have more than one active IP network adapter, a window pops up to let me select which adapter I want to have RSLinx use.

VPNs are built and tested mostly for HTTP, FTP, and file transfer applications and can sometimes play havoc with protocols developed for convenience on industrial LANs. Be patient and persistent and you'll get it working.

[scottmurphy]

Be patient and persistent and you'll get it working.

I think that was the key Ken, looked at it from a different angle, and it came right.

I was using the ETHIP driver, i went back to the Ethernet Devices driver, added in the IP address of the devices that I wanted to go to, and voila, they all appeared, and have been able to go online and do the changes that I need to.

In recent versions of RSLinx Classic, you can add ":EIP" to the end of the IP addresses you list in the Ethernet Devices driver configuration to skip the Port 2222 attempts.

I tried this, but as soon as I click apply, the :EIP disappears?


Thanks for you help Ken, must owe you a beer for that one...hows you PV+ knowledge, have runtime memory issues on the PV's at the moment. Looks like it is occuring after a few days, resetting the terminal clears the issue in the interim.

[Rgoltsch]

Here it is 2 years since the last post and I found this thread. I was trying to connect to a machine and was having little success. I wound up trying Ethernet Devices after seeing the previous post. It worked for me this time......

Thanks for the suggestion.

Ron