Siemens Enhanced Driver — AglNotConnectedException on Ubuntu after migrating from Windows

Ignition
,
1

I recently migrated our Ignition Gateway from a Windows host to a new Ubuntu machine, keeping the exact same device connection configuration (Hostname, Port 102, Rack/Slot, Address Type, Secure Connection Mode = PREFERRED). The connection worked reliably on Windows and immediately started failing on Ubuntu with the same settings.

Ignition version: 8.3.8
OS: Ubuntu 26.04 LTS (previously working on Windows with identical device configuration)
Driver: Siemens Enhanced Driver
PLC: Siemens S7-1200G2, firmware V4.1

I recently migrated our Ignition Gateway from a Windows host to a new Ubuntu machine, keeping the exact same device connection configuration (Hostname, Port 102, Rack/Slot, Address Type, Secure Connection Mode = PREFERRED). The connection worked reliably on Windows and immediately started failing on Ubuntu with the same settings.

Error observed

Initially:

org.eclipse.milo.opcua.stack.core.UaException: Next reconnect attempt in 26999 ms
at com.inductiveautomation.ignition.drivers.siemens.SiemensS7Client.withConnection(SiemensS7Client.java:247)
at com.inductiveautomation.ignition.drivers.siemens.SiemensS7Client.loadSymbolsFromPlc(SiemensS7Client.java:151)
at com.inductiveautomation.ignition.drivers.siemens.SymbolFsm$SymbolFsmFactory$ClientActions$1.loadSymbolInfo(SymbolFsm.java:688)
...

After further digging, the underlying cause surfaces as:

de.deltalogic.accon.aglink4.AglNotConnectedException: 'symbolic_LoadAGLinkSymbolsFromPLC': not connected. Connect to Plc with AglPlcConnection.connect().
at de.deltalogic.accon.aglink4.AglConnection.checkIfConnected(AglConnection.java:301)
at de.deltalogic.accon.aglink4.AglPlcConnection.symbolic_LoadAGLinkSymbolsFromPLC(AglPlcConnection.java:1599)
at com.inductiveautomation.ignition.drivers.siemens.SiemensS7Client.withConnection(SiemensS7Client.ja

So it looks like AGLink (the Deltalogic library backing the Siemens Enhanced Driver) is failing to establish the actual S7/COTP session on top of the TCP connection, even though the underlying TCP connection to the PLC succeeds.

What I've already verified/ruled out

  • Network layer is fine: from the Ignition host itself,
  ping -c 4 10.15.1.1

returns 0% packet loss, and

  nc -zv 10.15.1.1 102

confirms the port is open and responding as tcp/iso-tsap. So this is not a routing/firewall/cabling issue.

  • GLIBC version: ldd --version reports GLIBC 2.43, well above the documented minimum of 2.34 for x64 required by the Siemens Enhanced Driver as of the AGLink update for S7-1200 G2 support.
  • OpenSSL symlinks: per the manual's "Required Symlinks" section for the Siemens Enhanced Driver on a clean Linux install, I checked /usr/lib/x86_64-linux-gnu/ and both libssl.so -> libssl.so.3 and libcrypto.so -> libcrypto.so.3 were already present (attempting to create them manually returned "already exists"), so this isn't a missing-symlink issue either.
  • Device configuration is identical to the working Windows setup — same Hostname, Port 102, Rack/Slot, Address Type (Symbolic), Secure Connection Mode = PREFERRED.

Has anyone seen AGLink fail to establish a session (AglNotConnectedException) specifically after moving the Gateway host from Windows to Linux, with an otherwise identical configuration and confirmed TCP/102 reachability? Is there a known platform-specific AGLink/TLS behavior difference between Windows and Linux for the Siemens Enhanced Driver that I should be aware of, particularly around Secure Connection Mode = PREFERRED?

Any pointers appreciated — happy to share full wrapper.log output if useful.

Thank you

2

You should open a support ticket.

3

Do you have the IEC 61850 driver installed too?

4

Hello, yes I have

5

If you aren't using it, can you try uninstalling it?

6

Thanks a lot, this actually solved it! I uninstalled the driver and the Siemens Enhanced Driver connected immediately afterward.

Out of curiosity — do you know why having that driver installed alongside the Siemens Enhanced Driver was causing the AGLink connection to fail? I'd like to understand the root cause (shared library conflict, port/resource contention, something else?) in case it comes up again on other Gateways.

Thanks again for the help!

7

Yes, it's something to do with a change in 26.04, the Siemens driver using the system OpenSSL libraries, and the IEC 61850 driver loading an OpenSSL version embedded within the module.

It doesn't seem to be an issue on older versions of Ubuntu.

In 8.3.9 the 61850 driver will have a system property that can be set to make it use the system-provided OpenSSL rather than its own.