Resolving TIA Portal V13 Device Proxy HMI Endpoint Error

Problem Overview

When compiling an HMI configuration that uses the Device Proxy resource in TIA Portal V13, the compiler halts with the following diagnostic:

The combination of the local end point and the partner end point is not supported by the HMI connections.

The error is observed in mixed-vintage projects where a TP700 Comfort panel is connected to a SIMATIC CPU 316-2DP (6ES7316-2AG00-0AB0) or equivalent S7-300/400 controller, and the panel project was originally created in an older TIA release (V11 / V12) and migrated forward. Identical projects compile cleanly when the HMI/PLC interface is PROFINET, but fail the moment the engineer switches the connection resource to PROFIBUS (MPI/DP).

The Device Proxy feature is itself a TIA V13 introduction; it does not exist in V11 or V12 in the current form. It exposes the partner PLC's tag surface (data blocks, I/O symbols) to the HMI editor as a flattened OPC-style namespace, so the panel does not need a duplicated tag list. When the proxy cannot resolve both endpoints of a connection to a mutually supported transport, the compiler aborts and the message above is written to the Inspector pane.

Affected Versions and Components

Root Cause Analysis

Three independent root causes can produce the identical compile-time text. They are listed in descending order of frequency as reported on Siemens Technical Forum and confirmed in field service notes:

1. Version skew between the TIA Portal shell and the HMI device image. The Device Proxy data model was introduced with TIA V13; the runtime expects the panel firmware to be 13.0.1.0 or later. If the migrated HMI station is still running an 11.0.2.0 image, the proxy metadata emitted by the compiler references an endpoint pair that the older runtime firmware simply does not implement. The compiler therefore reports the endpoint pair as unsupported.
2. PROFIBUS S7 connection resource selected instead of PROFINET. The Device Proxy code path was first released to support PROFINET-only HMI connections. When the engineer drags the device proxy onto the HMI station and then opens the connection properties and changes the interface from PROFINET to PROFIBUS DP, the HMI compiler checks the partner endpoint against its local endpoint table and refuses the combination, because the proxy has not been qualified for PROFIBUS transports in the V13 base release. This is the most common failure mode and was reproducible on a freshly built test project.
3. Stale patch level of the TIA Portal installation. V13 SP0 shipped with known defects in the device proxy / HMI connection endpoint negotiation. Siemens aggregated the corrections into UPD6 for V13 SP0 and UPD4 for V13 SP1; both update packages are mandatory for projects that consume the device proxy.

Symptoms and Diagnostic Information

Before applying a fix, capture the following data so the same issue can be reproduced and verified later:

1. In the Project Tree, expand HMI_1 > Connections and double-click the failing connection. The Properties dialog opens on the General tab.
2. Note the Partner dropdown value, the Interface value (PROFINET interface / PROFIBUS interface), and the Connection mechanism value (S7 connection / TCP).
3. Click the small green arrow at the right of the error entry in the Inspector window. The compiler jumps to the exact line in the device proxy that fails. Confirm that the highlighted line is the ConnectionResource property.
4. From Project > HMI_1 > Device > Properties > General > Device Version record the image version (for example 11.0.2.0). The Device Proxy will only be coherent with the TIA Portal major version on the engineering side.
5. From the Windows start menu, launch SIMATIC Automation Tool or open Control Panel > Programs > Programs and Features and read the exact TIA Portal build string (TIA Portal V13 SP0 UPD6 = 13.00.00.00.06). The build string is what determines whether the fix is installed.

Resolution Path A - Update TIA Portal to V13 SP0 UPD6

Use this path when the engineering workstation is locked to TIA V13 SP0 and cannot be migrated to V13 SP1 or V14.

1. Close all TIA Portal instances and stop the Siemens SIMATIC TIA Portal background services from services.msc.
2. Download the latest TIA Portal V13 SP0 update package from the Siemens Industry Online Support entry TIA Portal V13 SP0 Update 6 (Entry ID 90466591). The download is provided as a self-extracting .exe archive; the file is approximately 2.4 GB and requires administrative rights.
3. Run the installer. Accept the license agreement and confirm the installation target. The installer restarts the S7DOS Help Service and the TIA Portal agents automatically.
4. After the installer finishes, open Control Panel > Programs and Features and confirm the entry reads TIA Portal V13.0 (13.00.00.00.06).
5. Re-open the project. TIA Portal will prompt to upgrade the project from the previous version; accept.
6. Right-click the HMI station and choose Compile > Software (rebuild all). The endpoint error must no longer be raised.

Resolution Path B - Update the HMI Image to Match the Portal

This path is preferred when the HMI station was migrated from a TIA V11 project and the panel itself is still flashing the V11 image.

1. In the Project Tree, right-click the HMI station (for example HMI_1 [TP700 Comfort]) and choose Change device > SIMATIC HMI > TP700 Comfort. In the version dropdown select the latest 13.0.1.0 image that matches the TIA Portal version.
2. Confirm the change. TIA Portal automatically re-maps the tags, screens, and alarms to the new device version.
3. Open the HMI connection properties and verify that the Partner still points to the S7-300/400 CPU and that the Interface matches the physical wiring.
4. Re-compile the HMI station. The endpoint pair should now resolve because the panel runtime image understands the device proxy schema introduced in TIA V13.

Resolution Path C - Correct the Connection Resource (PROFIBUS vs PROFINET)

Use this path if the error appears only after switching the HMI connection interface from PROFINET to PROFIBUS DP. The Device Proxy in TIA V13 does not accept PROFIBUS partner endpoints in the same way as PROFINET partner endpoints.

1. Open Devices & Networks and select the HMI station.
2. In the inspector, switch to the Connections tab. Click the HMI connection entry.
3. In the Properties pane, set the Interface of the partner to the PROFINET interface of the CPU. If the CPU has no PN port, drag a HMI Connection with the S7 protocol and point it at the CPU's PROFINET interface (for CPUs that have a PN/PN coupler) or convert the application to a classic S7-300 PROFINET HMI station.
4. As an alternative, abandon the Device Proxy and build a conventional tag list. Drag the HMI tags from the CPU into the HMI tag table manually. This bypasses the proxy negotiation entirely and is the recommended path for PROFIBUS-only panels.
5. Compile the HMI station to confirm the error is gone.

Device Proxy Feature Boundaries in TIA V13

The Device Proxy has well-defined scope limits in TIA V13. These limits frequently surprise engineers who expect the proxy to act as a generic S7-300/400 import. Use the table below as a reference when planning a migration.

The Device Proxy first became available with TIA V13. It is not a feature of TIA V12 or earlier. If the project is published to a V12 portal, the proxy is silently ignored and only the local HMI tag table is used.

Verification Procedure

1. Re-compile the HMI station with Compile > Software (rebuild all). The Inspector must show no errors and no warnings related to endpoint or connection resource.
2. Open the HMI connection and confirm the Status field at the bottom of the Properties dialog reads OK instead of Not compiled.
3. Right-click the device proxy and choose Go to partner. The cross-reference must jump to the matching connection in the partner PLC.
4. Download the HMI project to the panel using ProSave or TIA Portal's Online > Download to device. The transfer must complete without raising a connection-diagnostic alarm.
5. On the panel, open Start Center > Settings > System Information and verify the panel firmware image version matches the TIA Portal version (for example 13.0.1.0).
6. Establish a live connection from the panel to the PLC and confirm that the HMI tags bound through the device proxy are updating. A tag polling for a Boolean at DB100.DBX0.0 is a useful smoke test.

Troubleshooting Matrix

Field-Commissioning Caveats

• Proxy regeneration on CPU change. If the S7-300 CPU is replaced (for example a 314 to 316 upgrade), the device proxy must be deleted and re-created. The proxy binds to the original CPU's article number and module fingerprint, and a silent mismatch may not surface until the next full compile.
• Stepped versioning. TIA Portal does not allow downgrading an HMI image through "Change device". If a project is opened in V13 SP0 UPD6, the panel image will be lifted to 13.0.1.0. To roll back, the panel must be re-flashed from ProSave with a pre-V13 image, which in turn forces the panel project back to a V11 schema.
• Concurrent user logins. TIA Portal enforces a single writer on the project database. If two engineers have the same project open on different workstations and one of them applies UPD6, the second will see a version-skew prompt on next save. Always archive the project before patching.
• PROFIBUS and S7 routing. When the panel is on PROFIBUS and the CPU is on PROFINET, the device proxy will not bridge the two networks. A PN/PN coupler (for example 6ES7158-3AD10-0XA0) is mandatory, and the connection properties must be set to the coupler as the partner.
• Memory budget on TP700 Comfort. The Device Proxy is loaded into the panel's user memory. A deeply nested UDT structure can consume 200-400 kB on the panel. Confirm the available user memory in HMI > Properties > Memory before commissioning large proxies.

Related Standards and Manuals

• SIMATIC TIA Portal V13 SP0 Update 6 - SIOS entry 90466591
• SIMATIC TIA Portal V13 SP1 Update 4 - SIOS entry 109310176
• SIMATIC S7-300 CPU 31xC and CPU 31x: Operating Instructions (Entry 109311120)
• SIMATIC HMI TP700 Comfort Operating Instructions (Entry 109749617)
• PROFINET specification (PI organization) for reference on endpoint / AR semantics

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