Hello, i searching for a solution to connect a RUTX11 with a Siemens S7-1200 PLC.
I spent a lot of time in research, but i still have no final solution.
I wondering why so many “Siemens S7 oder Siemens PLC” Question was asked here, but all of them was automatically closed without a Information if it’s worked or not.
Best regards Robert
Good afternoon,
Please clarify what issues you are encountering. What you have tried. Potentially upload screenshots of your issue or configuration, while hiding sensitive information.
Regards,
Arturas
I’ve a brief intro for you. s7-1200 uses unroutable L2 (dcp) for configuration. This works when connected directly to the plc/lan. Search for profinet dcp. It is possible to do L2 remotely but it is not easy and mostly not worth the hassle.
Once a 1200 is configured you can use L3 access which is routable. Use e.g. openvpn or wireguard to access. The only thing that does not work is dcp, so configuring plc ip-addr, profinet-io or remote-io, search for devices does not work. Because they use L2 a protocol (no ip address, mac addrs!)
The problem has more to do with this weird profinet using both L2 (dcp, lldp) and L3 tcp/udp ip. It’s the L2 that bites you.
hih
let me add: even some switches blocks profinet L2 traffic! So this is not a teltonika only thing
Hi there,
PROFINET DCP operates at the Ethernet link layer (Layer 2), not using IP addresses but MAC addresses for device discovery and configuration tasks such as setting device names and IP addresses.
This means DCP traffic is unroutable across Layer 3 networks (IP networks), so it only works when devices are on the same local network segment or directly connected to the PLC or LAN.
Attempts to use DCP remotely over routed networks generally fail because Layer 2 multicast and broadcast packets do not traverse routers, and some network switches may even block PROFINET Layer 2 traffic like DCP or LLDP
Once the S7-1200 PLC is configured with its IP address and device name, you can access it remotely using routable Layer 3 protocols, for example, via VPN solutions like OpenVPN or WireGuard.
However, remote Layer 2 functions such as DCP-based device discovery, IP address configuration, or remote IO device search will not work over these routed connections because these functions rely on Layer 2 multicast/broadcast traffic that cannot be routed.
This limitation is not specific to Teltonika routers or any single vendor; it is a general characteristic of PROFINET and Layer 2 protocols, and some network switches may block or filter PROFINET L2 traffic, further complicating remote Layer 2 access.
Regards,
Good evening.
Thank you for the answers.
My programmer will check the settings and make a few screenshots next few days.
Best regards Robert
Good evening.
My programmer found the problem and can programm my PLC remotely now.
When he is back, he want tell me what’s the change that is run now.
Best regards Robert