OP77B PSR Backup File: Restoring and Migrating Siemens HMI

Overview: The PSR File and OP77B Mismatch

The Siemens SIMATIC OP77B is a compact 4-inch text/graphic HMI panel from the legacy OP7x series, designed primarily for S7-200 and S7-300/400 PLC integration via PPI, MPI, and PROFIBUS DP. The panel is a direct successor to the OP7, OP17, and OP27 text-based panels and re-uses much of the same screen architecture while adding 4-bit grayscale graphics and an expanded tag database.

When a field engineer receives a backup file with a .psr extension (typically 200 KB to 2 MB depending on project complexity) and attempts to use it on an OP77B, the file will not open, the restore will fail, and the configuration software (ProTool or WinCC Flexible) will reject the file with format errors or device-type mismatches. The .psr extension is the backup file format used by older Siemens text-based HMI panels (OP3, OP5, OP7, OP15, OP17, OP25, OP27, OP35, OP37) and the corresponding first-generation graphic panels. The OP77B uses the .psb backup format and is configured with WinCC Flexible (2004 SP3 and later) or ProTool/Pro V6.0 SP3. There is no direct converter from .psr to .psb, and a .psr backup cannot be re-flashed onto an OP77B because the runtime firmware, screen architecture, and tag database of the older OP series are not byte-compatible with the OP77B firmware.

This article documents the diagnostic workflow for a .psr-on-OP77B scenario, the correct ProSave procedure for OP77B backup and restore, the migration path from the older OP panel family, and the recovery options when only a .psr backup exists without the original editable project file.

Siemens HMI Backup File Extension Reference

The Siemens SIMATIC HMI product line uses several distinct backup file extensions, each tied to a specific panel family and configuration tool. Mixing extensions across families is the most common cause of "cannot open file" errors in the field.

The crucial distinction is that .psr and .psb are not interchangeable. ProSave checks the device type embedded in the backup header and refuses to write a .psr image to an OP77B even if the file is renamed to .psb, because the internal structure (recipe database layout, alarm buffer, screen ID space, tag address map) differs between the older OP firmware and the OP77B firmware. The OP77B catalog number, the panel's firmware version, and the configuration tool's project version must all align for a restore to succeed.

Why PSR Files Don't Open in ProTool or WinCC Flexible

ProTool and WinCC Flexible expect editable project files (.pdb/.pdl or .hmi), not compiled runtime backups. The .psr file is the result of compiling a project with ProTool and downloading it to the panel; it contains the runtime image, recipe data, and password database, but it does not contain the editable screen definitions, script logic, or tag database in a recoverable form for the OP77B configuration software.

When a user attempts to open a .psr backup in ProTool, the application reports that the file is not a valid project ("The selected file is not a ProTool project"). In WinCC Flexible, the project wizard will not recognize the .psr as a project file ("Unknown file format"), and ProSave (when pointed at a .psr file with the OP77B selected as the target) will fail with an error such as Backup file is invalid for selected device or Firmware version mismatch.

Even with the older OP series that produced the .psr file, the file cannot be "opened" and edited in ProTool; it can only be restored to a panel of the matching type. To recover the editable project from a .psr, the original .pdb or .hmi source must be located, or a partial upload must be attempted from a compatible panel that has been re-flashed with the .psr.

Identifying the Source Panel of an Unknown PSR File

When a .psr file is delivered without documentation, the source panel can be identified through a structured diagnostic sequence. The following procedure requires ProSave and a compatible panel from the legacy OP family (or the suspected source panel if available).

1. Inspect the file header. Open the .psr in a hex editor (HxD, 010 Editor, or similar). ProTool backups embed a header structure that includes the device type, firmware version, project ID, and compile timestamp. The first several bytes typically contain an ASCII identifier string followed by binary length and version fields. Document the offset positions of these strings for reference.
2. Document the file metadata. Record the file size, the embedded compile date (if visible in the header), and any text strings found in the header (project name, panel name, language code). A 536 KB .psr is consistent with a moderate text-only project on OP7, OP17, or OP27. Projects with embedded graphics typically exceed 1 MB; pure text projects with extensive recipe and alarm databases may reach 2 MB.
3. Compare against known panel firmware images. If a Siemens firmware image (.img) for the suspected source panel is available, the header offsets can be cross-referenced. Siemens publishes firmware images on the SIMATIC Customer Support portal under "HMI Operator Panels" → "Updates and Utilities."
4. Attempt a restore on a compatible panel. If any panel from the OP3/OP5/OP7/OP15/OP17/OP25/OP27/OP35/OP37 family is available, connect via RS232 and run a ProSave restore. A successful restore confirms the source panel family and recovers the runtime behavior for screen-level inspection. If the restore fails with "Backup file is invalid for selected device", try a different family member.
5. Upload from the restored panel. Once the .psr is restored to a compatible panel, use ProTool's Upload Station function (not a backup) to retrieve the editable project. Note: upload from a text-based OP typically recovers screens, tags, and text tables, but custom graphics and complex scripts may not be fully reconstructible. The recovered .pdb may be incomplete and require manual cleanup before it can be re-deployed.

Figure 1: Decision flow for incoming Siemens HMI backup files

Restoring an OP77B: The Correct PSB Backup Procedure with ProSave

ProSave is the dedicated Siemens utility for OS update, backup, restore, and transfer of SIMATIC HMI panels. It ships as part of the SIMATIC HMI Toolset, WinCC Flexible, or TIA Portal (under the "ProSave" entry in the installation tree, accessible directly or via the WinCC Flexible Panel > Backup/Restore menu). For the OP77B, the relevant ProSave operations are:

• Backup (read): Reads the panel's runtime image, recipes, alarm buffer, and password table; writes them to a .psb file on the engineering PC.
• Restore (write): Writes a .psb file from the PC to the panel, overwriting the existing runtime image and on-panel data. The panel reboots into the restored project.
• OS Update: Updates the panel's operating system firmware from a .img file. Used to recover a panel with a corrupted or out-of-date firmware image.
• Transfer (PN/MPI): Used during initial commissioning to push the compiled project from WinCC Flexible / TIA Portal to the panel via MPI/PPI/PROFIBUS.

ProSave enforces strict type-checking: a .psb file generated from an OP77A, TP170A, or any other panel model will be rejected when restored onto an OP77B, even if the firmware versions match. The catalog number of the panel, the firmware version, and the configuration tool's project version must all align. A typical mismatch error is "Wrong device type" / "Falscher Gerätetyp" displayed in the ProSave status bar.

Step-by-Step ProSave Backup of an OP77B

1. Connect the engineering PC to the OP77B. Use a Siemens RS232 PPI/MPI cable (6ES7 901-3CB30-0XA0) for serial connection, or the optional Ethernet/MPI adapter if the panel is fitted with the IF1B Ethernet module. For modern PCs without a built-in RS232 port, use a USB-to-serial adapter based on the FTDI FT232 chipset (verified compatible); ProSave and WinCC Flexible transfer have been validated with FTDI-based adapters on Windows 10 and Windows 11.
2. Set the OP77B transfer mode. On the panel, navigate to Start > Settings > Transfer (or, on early firmware, hold the lower-left function key during startup). Enable transfer mode and note the MPI/PPI address (default 1) and baud rate (default 187.5 kbps for MPI, 9.6 kbps or 19.2 kbps for PPI). The panel displays "Transfer" in the status bar when ready.
3. Launch ProSave from Start > SIMATIC > ProSave (or from within WinCC Flexible under Panel > Backup/Restore). On TIA Portal installations, the path is Start > Siemens Automation > ProSave.
4. Configure the device type and connection. In ProSave, select General > OP77B as the device type. Select the connection type (Serial / MPI / PPI / Ethernet) to match the cable in use. Set the PC interface (COM1 / COM2 / COMx for USB adapters), baud rate, and station address to match the panel. For Ethernet connections, enter the panel's IP address and subnet mask.
5. Select the Backup tab. Enter the destination path and filename (e.g., C:\HMIBackup\OP77B_Project_20240115.psb). Enable the option to include recipes and alarm logs if required.
6. Click "Backup". ProSave negotiates with the panel, reads the runtime image, and writes the .psb file. A typical 512 KB–2 MB project takes 30–180 seconds at 187.5 kbps. At 9.6 kbps (PPI), the same transfer may take 5–10 minutes.
7. Verify the backup. ProSave displays a success message with a checksum. Store the .psb file in a versioned backup repository with a dated filename. Cross-check the file size against the project size in WinCC Flexible's project properties for sanity.

Step-by-Step ProSave Restore of an OP77B from a PSB File

1. Connect and configure ProSave as in the backup procedure (steps 1–4 above). Confirm the target panel is in transfer mode and reachable.
2. Select the Restore tab in ProSave.
3. Browse to the .psb file and select it. ProSave reads the backup header and displays the source panel model, firmware version, and project version.
4. Confirm that ProSave's reported device type, firmware version, and project version match the target panel. If there is a mismatch, ProSave will warn before proceeding. Do not override the warning unless you are intentionally downgrading or cross-loading.
5. Click Restore. The panel reboots, accepts the new runtime image, and restarts with the restored project. The transfer takes 30–300 seconds depending on the connection speed and project size.
6. After restart, verify screen rendering, tag polling, alarm buffer, recipe data, and any password-protected areas. Cycle the panel power once after a successful restore to ensure the runtime image is committed to flash.

Cable, Connection, and Communication Parameters

For ProSave operations, the most reliable connection is the IF1 RS232 port with a Siemens PC/PPI cable (6ES7 901-3CB30-0XA0). The cable's DIP switches must be set to the correct PPI/MPI mode, and the baud rate must be selected on both the cable and the panel. The cable's default MPI address is 0, but this can be reconfigured in the cable's setup utility.

Modern PCs (2015 and later) typically lack a built-in RS232 port. Two options for connecting to the OP77B:

• USB-to-serial adapter (FTDI chipset): The most reliable option. Verify the adapter uses the FTDI FT232 or FT231X chipset. Prolific PL2303-based adapters have known compatibility issues with ProSave on Windows 10/11 and may require legacy driver versions.
• Siemens USB PC/PPI cable (6ES7 901-3DB30-0XA0): The newer USB variant of the PC/PPI cable, designed for modern PCs. This is the recommended cable for new deployments.

Migration Path from Older OP Panels to OP77B

If the source panel is one of the older text-based OPs (OP3, OP5, OP7, OP15, OP17, OP25, OP27, OP35, OP37) and the OP77B is intended as a replacement, the migration is a rebuild, not a restore. The screen architecture differs (text-mode 4×20 vs. 160×48 / 240×64 pixel graphics), the tag database structure differs, and the variable addressing may need re-mapping to match the new PLC connection.

Recommended migration workflow:

1. Locate the original ProTool project (.pdb or .pdl). If unavailable, restore the .psr to a compatible OP panel and attempt a ProTool upload to extract a partial .pdb (text screens and tags only).
2. Inventory the screens, tags, alarms, and recipes from the original project. Document PLC addresses, message texts, language tables, and navigation structure. Photograph the screens of the running panel for visual reference.
3. Open a new WinCC Flexible project targeting the OP77B. Use the OP77B device template in the WinCC Flexible project wizard. The catalog number for the OP77B monochrome is 6AV6641-0BA11-0AX0; for the color variant OP77B Color, the catalog number is 6AV6641-0CA11-0AX0.
4. Recreate screens in the WinCC Flexible editor, using the OP77B's pixel-based graphics rather than the text-mode screens from the legacy OP. Re-use texts, message classes, and tag names where possible. Use the OP77B's native font (Tahoma 14/18/26 pt) for consistency.
5. Reconnect tags to the new PLC connection (PPI, MPI, or PROFIBUS). The tag names from the ProTool project can be preserved, but the data types and addresses must be re-validated against the current PLC program. Note that ProTool used 16-bit tag addressing; WinCC Flexible supports 32-bit and pointer-based addressing.
6. Recompile and transfer the new project to the OP77B via WinCC Flexible (Compile > Rebuild All > Transfer) or ProSave.
7. Commission and verify on-site: cycle power, validate screen navigation, force-tag test, alarm acknowledgment, recipe read/write, and password-protected area access. Document any deviations from the original project for the end-user's records.

Configuration Software: ProTool, WinCC Flexible, TIA Portal

Siemens' current recommendation for new installations is the SIMATIC KTP400 Basic, which is fully supported in TIA Portal as a native device. The OP77B is a maintenance-only product as of 2017; new development should not be started on the OP77B platform. For existing OP77B installations, the recommended support path is:

1. Maintain a WinCC Flexible 2008 SP3 installation on a Windows 10 engineering PC for project editing.
2. Use ProSave (bundled with WinCC Flexible or TIA Portal) for backup, restore, and OS update operations.
3. Archive the editable .hmi project file in versioned storage (Git, SVN, or a structured backup repository).
4. For TIA Portal integration (e.g., if the PLC is on TIA Portal), use the "Migrate WinCC Flexible project" function to import the .hmi file, then transfer to the OP77B via ProSave. TIA Portal does not have a native device profile for the OP77B.

Refer to the SIMATIC Customer Support portal for the latest OP77B operating instructions, firmware images, and Knowledge Base entries on WinCC Flexible compatibility with Windows 10/11.

OP77B Hardware Reference

Specifications are derived from the standard Siemens OP77B datasheet. Confirm against the official Siemens product documentation on the SIMATIC Customer Support portal before specifying for new projects.

Troubleshooting Matrix

Frequently Asked Questions