I can connect to Flexy and to the Machine Lan, but not to Compactlogix PLC

Ewon Support Ewon Flexy
#1

Hi,

I’m running into a strange problem with a customer.
I need to make some changes to the Compactlogix PLC, but I can’t connect to it.

The machine has:

  • 1 Compactlogix PLC
  • 2 Powerflex Drives
  • 1 Panelview 7 Touchscreen

Those are on the same machine lan and same subnet, they use ethernet/IP to communicate.
The machine is working as expected, so the machine lan works.
I can connect using the Ewon VPN to the Flexy and I can see the machine lan, but I can connect only to the Panelview Touchscreen, not to the PLC or the Drives.
Also in RSLINX I can see the touchscreen connect, but not the PLC or Drives.

Kindly note that in the past months I’ve connected to this machine several times and made changes to the PLC without any problems.
Nothing is changed to the PLC configuration or the lan hardware, so I can’t understand why I can’t connect any more to the PLC.

Kindly give me some advice on how to solve this problem. Thanks.

#2

Can you ping the PLC?

It sounds like your RSLinx driver setup. Make sure to add the PLC’s IP address in RSLinx.

1 Like
#3

Thanks Kyle for your reply.

I’m not able to ping the PLC but in RSLinx I have the PLC (10.0.0.100) and also the Touchscreen (10.0.0.105), I can ping and see active the Touchscreen in RSLinx, but not the PLC…this is quite strange.

Kindly note, as I wrote, that I connected, in the past months, several times to this machine and everything worked fine, nothing is changed but now I’m facing this problem.

#4

Was the NATitf setting in comcfg.txt changed?

It sounds like maybe the PLC and drives don’t have the correct default gateway setting. The default gateway should be the LAN address of the Ewon. If you change NATitf to 3, reboot the Ewon, you may be able to reconnect to them. That enables “plug and route” or NAT on LAN, so the default gateway isn’t required. (It will not take effect until after a reboot)

1 Like
#5

I’m not aware of any modification to comcfg.txt, anyway I’ll connect to Flexy and I’ll check it.
Thanks, I’ll check ASAP and I’ll return to you.

#6

Ok, I think I’ve found the problem.

A collegue of mine, due overlapping with IP addresses, has configured the “LAN Devices & Firewall” rules including just the IP address of the HMI because he needed to supervise the machine.
Now I’ve tried to add also the IP addresses for both the PLC and DRIVES and I can ping all devices.

I’ve also checked the NATitf and this is set to “Plug’N’Route” (3).

#7

OK great - thanks for the update!