Resolving *.s7p Device Proxy Import Failure in TIA Portal V20

When a Comfort Panel project is opened in TIA Portal V20 Update 1 and the engineer attempts to initialize a Device Proxy from a STEP 7 Classic archive (*.s7p), the file does not appear in the selection dialog. Only *.IPE and *.AP20 are listed as supported. The same workflow was fully functional in TIA Portal V18. The failure is not a project corruption, missing installation component, or license issue; it is a deliberate change in the TIA Portal device proxy importer for V20 and later. This reference documents the root cause, the exact affected versions, the supported file formats, and the three field-proven workarounds that restore a working HMI ↔ PLC link when the controller is an S7-400H (or any S7-300/400) programmed under PCS 7 / STEP 7 V5.x.

1. Problem Description

A typical user scenario:

1. An S7-400H (CPU 416H, article number 6ES7 416-3FR05-0AB0 or similar) is programmed in PCS 7 V9.0 SP2 on top of STEP 7 V5.7.
2. The automation project is archived with "File → Archive" into a STEP 7 Classic project archive: myplant.s7p.
3. The Comfort HMI project is created in TIA Portal V20 Update 1 using a TP1200 Comfort (6AV2 124-1MC01-0AX0) or similar.
4. The engineer adds a SIMATIC S7-400 device as "unspecified CPU 400" and tries to convert it into a Device Proxy by "Initialize device proxy" / "Load from STEP 7 project".
5. The file dialog lists *.IPE and *.AP20 but not *.s7p.
6. The same procedure succeeded in TIA Portal V18 using the same archive.

Symptom summary:

• "Initialize device proxy" wizard shows no *.s7p file filter.
• Renaming the file extension from .s7p to .ipe or .ap20 is rejected by the importer with error "The selected file is not a valid IPE/AP20 file."
• Drag-and-drop of the archive onto the Device Proxy node produces the same error.
• Compiling the HMI produces warnings such as "No connection partner configured for the proxy".

2. Root Cause

According to Siemens Industry Online Support entry 109975076 "Why is the selection of a STEP 7 Classic project (*.s7p) no longer possible for the device proxy in TIA Portal", the direct initialization or import of Device Proxies from STEP 7 Classic archives (*.s7p) has been removed from TIA Portal. The change applies to the TIA Portal versions listed in section 3.

The reason is the architectural shift toward Inter-Project Engineering (IPE) as the preferred exchange container between STEP 7 Classic / PCS 7 projects and TIA Portal. The IPE container encapsulates:

• The CPU type and firmware version
• The rack / slot configuration (including redundant slots for S7-400H)
• All configured DP / PN / PROFINET interfaces and ports
• The communication connections (S7 connections, S7 connection-substitute, HMI connections)
• The tag-relevant data block interface description (data type, length, comment, attributes)
• The HMI-relevant operator-authorization / area-pointer data

The *.s7p archive is a binary STEP 7 V5 container that mixes hardware configuration, S7 program, and symbol table. It was never designed to feed the TIA Portal's TIA-compiler-based device proxy engine. TIA Portal V18 accepted the legacy format through a transitional compatibility layer; the layer was deprecated and removed in TIA Portal V20.

3. Affected Versions

4. Supported File Formats for Device Proxy Initialization

The Inter-Project Engineering (IPE) workflow is the officially supported replacement. It is documented in the TIA Portal help under "Using team engineering → Exchanging data with Inter-Project Engineering (IPE) → Updating the device proxy data" — see Updating the device proxy data.

5. Prerequisites for the Workarounds

Before applying any of the three workarounds, the engineering station must have the following installed:

• STEP 7 V5.7 SP2 (or later SP) with the corresponding HF (hotfix) installed on a 64-bit Windows 10 / Windows 11 engineering station. STEP 7 V5.7 is still distributed and supported for parallel use with TIA Portal V20 on the same PC.
• PCS 7 V9.0 SP2 or V9.1 if the S7-400H is part of a PCS 7 plant. The PCS 7 engineering license is required to expose the "Create IPE file" entry.
• TIA Portal V20 Update 1 or V20 Update 2 / Update 3 with the matching HMI ProDiag / HMI Base Packages installed.
• S7-PCT (Port Configuration Tool) V3.5.1.4 or later if PROFINET port interconnection must be transferred to the proxy.

6. Workaround A — Export IPE from STEP 7 V5.7 / PCS 7 (Recommended)

This is the Siemens-supported path. It does not require touching the S7 program source and is fully round-trip-capable (you can re-import an updated IPE later).

6.1 Procedure

1. Open the S7 project in SIMATIC Manager (STEP 7 V5.7) or PCS 7.
2. Select the S7 program / station that owns the target CPU (e.g. AS01 / S7 Program(1) for the CPU 416H).
3. Right-click the station → "Create IPE file" (German: IPE-Datei erzeugen). The menu entry is enabled only if the project has been compiled without errors (HW Config + NetPro + S7 program all in green state).
4. In the dialog, set the scope:
   • Station: include HW Config and CPU connections
   • S7 program: include data blocks marked "S7-mappable" (HMI-relevant DBs)
   • Symbols: include so the IPE preserves symbolic tag names
5. Choose a target path, e.g. D:\ipe\AS01_proxy.ipe.
6. Click OK. STEP 7 produces a single binary IPE container. A success log entry is written: "IPE file 'AS01_proxy.ipe' successfully created, 1 CPU, 4 S7 connections, 312 tags."

6.2 Import the IPE into TIA Portal V20

1. Open the Comfort HMI project in TIA Portal V20.
2. In the project tree, expand the "Unspecified CPU 400" device node.
3. Right-click "Device proxy" → "Initialize device proxy".
4. Browse to the IPE file (AS01_proxy.ipe).
5. The Device Proxy is re-materialized with the correct CPU order number, firmware, rack layout, and configured S7 connections.
6. Tags from the HMI-relevant DBs appear under "PLC tags → Proxy tags".

After import, the *.IPE file should be stored under Project management → Documents and tracked under version control so that subsequent STEP 7 changes can be re-imported using the "Update device proxy" command.

7. Workaround B — Use *.AP20 (TIA-native archive)

If the engineer has access to a TIA Portal V20 copy of the CPU's project (e.g. a parallel S7-1500 / S7-1200 station in the same plant that already runs in TIA), the AP20 archive can be used.

7.1 Procedure

1. In the TIA Portal V20 source project, select the S7 device.
2. Project → Archive → Project archive (*.ap20). Tick "With Hardware configuration and software" and "With team engineering IPE data".
3. Save as AS01_AP20_backup.ap20.
4. Open the Comfort HMI project, initialize the Device Proxy from this *.ap20.

This is a full-project archive, so it is larger and slower than an IPE file. It is the right choice when the controller is already fully migrated to TIA Portal and the STEP 7 Classic source has been retired.

8. Workaround C — Down-Edit in TIA Portal V18 and Migrate

Use this path only when an IPE export cannot be generated (legacy STEP 7 V5.4/V5.5 source, missing IPE support patch) and the plant cannot be re-engineered in TIA. The conversion is a one-shot, but the resulting TIA project is fully editable in V20.

1. Open the project in TIA Portal V18 Update 4 on a separate engineering station (or a parallel installation).
2. Use Project → Migrate to TIA Portal to import the *.s7p.
3. Open the migrated project in TIA Portal V20 (the migration produces a V18 project; "Project → Open with version → TIA Portal V20" upgrades it).
4. Export the S7 station as *.ap20 and re-initialize the Device Proxy in the HMI project as in Workaround B.

9. S7-400H-Specific Considerations

An H-system has two CPUs in slots 3 and 4 of two identical racks. The Device Proxy must reflect the redundancy role and the H-sync module configuration. When initializing from an IPE file, the following items must be present in the STEP 7 V5.7 source:

• CPU 416-3 (6ES7 416-3FR05-0AB0) or 416-3FH (6ES7 416-3FT05-0AB0) with matching order number (F-CPU part numbers differ and must match the IPE export).
• Synchronization modules (Y-link) and Sync-domain 1 defined under "Configure → Synchronize" for both CPU racks.
• Fault-tolerant S7 connections to the OS servers (HMI). These show up in the IPE as S7 connection - redundant.
• PN/IE interfaces: rack 0 / slot 3 X5 port 1 and rack 1 / slot 3 X5 port 1 must be on the same PROFINET subnet used for H-sync.

If the IPE export logs "H connection data incomplete: 1 of 4 S7-H connections missing", open NetPro → select the missing H connection → Properties → tick "Active connection establishment" on both ends, recompile, and re-export. A corrupt H-connection set is the most common cause of a proxy that initializes but is missing connection points in the HMI.

10. Comfort HMI Configuration with the Proxy

Once the Device Proxy is loaded, the HMI configuration must reference it through a PROFINET IO proxy or S7 routing:

1. In the HMI device configuration, double-click "PROFINET interface [X1]".
2. Set "Connection to PLC" to "PROFINET IO".
3. Set "PLC proxy" to the CPU 416H Device Proxy node in the project tree.
4. Confirm the IP address (HMI) and subnet (CPU 416H PN-IO port) match the PCS 7 plant subnet.
5. If the HMI is on a sub-network separate from the AS, enable "Use router" and enter the SCALANCE / PN/PN coupler IP.

Verification step: open the HMI connection table (HMI device → "Connections") and confirm that the IP, rack, slot, and connection resource match the NetPro definition in STEP 7 V5.7. A mismatch of the connection resource (e.g. local: 03 / partner: 03 swapped) is a common fault after IPE import.

11. Verification Checklist

12. Troubleshooting Matrix

13. Field-Proven Caveats and Edge Cases

• OPC UA server tags on the CPU 416H are not included in the IPE. They must be added manually on the HMI side as "Tag prefix" definitions if the HMI consumes OPC UA.
• Modbus / PN coupler area pointers (e.g. WordToBool) survive the IPE export only if the PN/PN coupler is configured in the same STEP 7 V5.7 project as the CPU. A separate "coupler project" requires a manual tag addition in TIA.
• Redirected IPE files (network shares) may fail to import with a permission error if the engineering account does not have "modify" rights. Always copy the IPE to %LOCALAPPDATA%\Siemens\Automation\ipe before importing.
• Multi-user server (MUL) projects: the Device Proxy must be re-initialized by the user that owns the IPE file in PLM; otherwise the local proxy will be overwritten on the next "Check in / Get latest version".
• Safety (F-CPU) related S7-connection safety signature is encrypted in the IPE; if the source project was archived before safety program acceptance, the IPE import log will show a warning "F-signature not present". This is a non-fatal warning, but the F-commissioning workflow must be re-run on the TIA side.

14. Long-Term Recommendation

Plan a phased migration of all STEP 7 V5.7 / PCS 7 plant projects into TIA Portal V20 / V21 with the device proxy maintained as a re-imported IPE reference. Establish a controlled ipe/ directory in your version control, define a versioned IPE naming scheme (e.g. AS01_proxy_v1.4.ipe), and treat the IPE as a contractually binding artifact. The TIA Portal help chapter "Updating the device proxy data" (see docs.tia.siemens.cloud) covers the full update cycle: import the new IPE → confirm communication relations → publish the new tag set to the HMI → recompile.

15. Related Standards and References

• Siemens Support entry 109975076 — Why is the selection of a STEP 7 Classic project (*.s7p) no longer possible for the device proxy in TIA Portal?
• TIA Portal Online Help — Updating the device proxy data