Resolving Siemens MP277 Transfer Failure After Corrupt SD Restore

Problem Details

The Siemens SIMATIC MP277 10" Touch is a Windows CE-based HMI panel that, after a partial or corrupted restore from an SD card, can enter a boot loop where the bootloader window (Start / Transfer) appears for less than a second and is then replaced by the dialog Restore: Abort Restore. Remove storage card! Acknowledging the dialog triggers an immediate reboot, which prevents any network or USB transfer from establishing. The panel remains visible in the engineering station's accessible nodes list (S7ONLINE / STEP 7) and responds to ICMP echo, but WinCC flexible and ProSave cannot complete a transfer handshake.

Observed Symptoms

• Bootloader window flashes for under one second during startup.
• "Restore: Abort Restore. Remove storage card!" dialog interrupts the bootloader.
• Acknowledging the dialog causes an immediate reboot.
• WinCC flexible Transfer dialog never sees the panel even when pingable.
• STEP 7 / S7ONLINE accessible nodes discovery succeeds (TCP/IP) but the transfer fails with a connection timeout.
• A recent OS update was performed before the fault, and the panel does not implement a button-based factory reset.

Affected Hardware and Software

Root Cause Analysis

The MP277 firmware searches the SD card slot at boot for a pending restore image (path \Storage Card\Simatic.HMI\Backup\ or \Storage Card\Restore\ depending on the firmware build). If the image header is invalid, partially written, or incompatible with the currently installed OS version, the panel aborts the restore, displays the error dialog, and reboots to re-attempt the operation. Because the panel re-issues the abort dialog on every boot, the user is locked out of the regular transfer mode used by WinCC flexible and ProSave.

Three concurrent factors typically produce the field failure described in the source case:

1. Corrupt or mismatched SD restore image. A backup created on a different firmware build, or an interrupted write to the SD card, leaves a header that the panel refuses to apply.
2. OS upgrade before the failed restore. Updating the panel OS without first re-creating a compatible backup makes any prior backup file effectively unusable on the new firmware, especially if the runtime image format changed between minor releases.
3. Transfer service not started. Even after the SD card is removed, the boot sequence is short enough that the WinCC flexible / ProSave transfer service (S7 protocol over TCP/102 and the WinCC flexible handshake on TCP/8000) is not ready when the host application begins discovery, so the panel appears reachable but the transfer state machine never completes.

On the MP277 10" Touch, the bootloader does not implement a button-based factory reset the way the MP 377 and Comfort Panels do (for example, "Select + Power" recovery). The only sanctioned factory reset is the ProSave OS-update path, which is why Methods 2 and 3 below focus on ProSave and the PC/PPI multimaster cable.

Solution Methods

Use the methods below in order. Method 1 is non-destructive and recovers the panel without dismantling it. Method 2 is required if Method 1 cannot enable Ethernet transfer. Method 3 is the last-resort hard reset path over MPI/PPI.

Method 1 - Clear the Storage Card Slot and Force Transfer Mode

1. Power off the MP277 (disconnect the 24 V supply, wait 10 seconds, restore power).
2. Remove the SD card completely. Do not leave it in the slot. The panel continues to attempt the restore as long as a card is inserted and the image header is rejected.
3. Power on the panel. The "Restore: Abort Restore. Remove storage card!" message will still appear because it is queued from the previous boot. Acknowledge the dialog and let the panel reboot.
4. On the second reboot, the bootloader window should remain on screen long enough to select Transfer. If the bootloader still flashes past, proceed to Method 2.
5. In the Transfer dialog, set the panel IP address, subnet mask, and gateway to match your engineering network (for example, 192.168.0.1 / 255.255.255.0).
6. Confirm Enable Transfer is checked. Exit to the Start Center.
7. From the engineering PC, launch WinCC flexible and select Project → Transfer → Transfer (or Commissioning → Transfer). Select Ethernet / TCP/IP, enter the panel IP, and start the transfer.

Method 2 - ProSave OS Update with "Reset to Factory Settings"

If Method 1 fails to expose the panel long enough for a transfer, use ProSave to push a clean OS image to the panel and simultaneously clear the corrupted restore state. ProSave's OS update operation with Reset to factory settings forces the panel to reformat its internal flash and reload the image. On the MP277 10" Touch this option is available over Ethernet and over a PC/PPI multimaster cable as a fallback. For the cabling options that work with SIMATIC Panels, see the Siemens support article Which connector cables are available for connecting to SIMATIC Panels?.

1. Install or update ProSave on the engineering PC. The version must match or exceed the panel firmware; for MP277 with Windows CE 5.0 images, use ProSave from the WinCC flexible 2008 SP5 DVD or later.
2. Connect the PC and the panel:
   • Ethernet path (preferred): use a crossover cable or a switch. Set the PC to a fixed IP in the same subnet as the panel (for example, panel 192.168.0.1, PC 192.168.0.10).
   • PC/PPI multimaster cable path (fallback): connect the 6ES7 901-3DB30-0XA0 cable to the panel's MPI/DP port and the PC's serial port (or via a USB-serial adapter).
3. Launch ProSave. In the Device field, select MP277 Touch or use Device type… → search to confirm the panel is detected.
4. Set the Connection to Ethernet and enter the panel IP, or to PC/PPI cable if using the serial path.
5. Open the OS update tab.
6. Check the option Reset to factory settings. When selected, ProSave prompts for the panel's MAC address; enter the value printed on the rear label (format xx:xx:xx:xx:xx:xx).
7. Select the image file (.img) shipped with WinCC flexible. The standard path is …\<WinCC flexible>\Images\<panel>\ (for example Images\MP277 Touch 10\).
8. Click Update OS. The panel will reboot into update mode, write the image, and re-format its flash. This process takes approximately 4-8 minutes for a 10" Touch. Do not power off the panel during the operation.

After the panel reboots, the SD card slot state is cleared and the panel returns to the standard transfer / start menu. The project name shown on the Start Center will be CE_Restore until a project is transferred. Proceed to Method 3 to reload the project. The detailed OS update procedure is documented in the Siemens support article how do you do an "Operating system update" (OS update) or "Reset to factory settings" on operator panels?.

Method 3 - PC/PPI Multimaster Cable Direct Transfer

For panels whose Ethernet service does not start (or for engineers without a free Ethernet switch), the legacy PC/PPI multimaster cable provides a guaranteed path. The cable is identified by Siemens part numbers 6ES7 901-3DB30-0XA0 (RS-232 PPI) or 6ES7 901-3DB30-0XA1 (USB). Set the cable's DIP switches to PPI / 19.2 kbps / master mode.

1. Set the panel's MPI/DP transfer parameters: Control Panel → Transfer → MPI/DP → address 1, 19.2 kbps, master off (panel is a slave on PPI).
2. On the engineering PC, configure the same baud rate in Set PG/PC interface → PC/PPI cable (PPI).
3. In WinCC flexible, choose Project → Transfer → Transfer with the MPI/DP option and station address 1.
4. Once a project is restored, generate a fresh backup via ProSave (Backup → to storage card) and copy it to an SD card of 8 GB or smaller, formatted FAT32, to avoid repeat failures.

Why WinCC Flexible Shows the Panel in Accessible Nodes but Fails to Transfer

The MP277 publishes an S7 discovery response on TCP/102 that is visible to STEP 7 and to the Windows network browser. WinCC flexible uses a different transfer handshake that requires the panel's Transfer service to be in a waiting state. When the bootloader aborts the restore before the transfer service is initialized, the discovery works (panel is reachable) but the transfer handshake never completes and WinCC flexible reports "Cannot establish a connection" or times out after 30-60 seconds. Forcing the panel out of the restore loop (Methods 1 and 2) is the only way to put the transfer service in the correct state.

Verification

After completing Method 1, 2, or 3, verify recovery with the following checks:

1. Panel boots to the standard Start Center (no abort dialog). The project tile shows the expected project name or, after a factory reset, the default name CE_Restore.
2. From the engineering PC, ping <panel_ip> returns replies with TTL consistent with Windows CE (typically 50-64).
3. In WinCC flexible, the transfer dialog lists the panel in Available nodes with the project name CE_Restore (default name after a factory reset) or the previously loaded project name.
4. Project compiles cleanly and the transfer completes in under 90 seconds for a 10" project of typical size.
5. After the project loads, use ProSave → Backup → to storage card to create a fresh restore image. Power-cycle the panel once with the card in place to confirm the restore path works end-to-end.

SD Card Best Practices for HMI Backup and Restore

• Use SD cards of 8 GB or smaller formatted as FAT32. The MP277 does not support exFAT and aborts the restore if it cannot read the file system.
• Always wait for the panel's "Backup complete" or "Restore complete" dialog before removing the card. Hot-removal during a write is the most common cause of corrupted backup images.
• After any OS update, regenerate the backup. A backup created on firmware version X will not restore cleanly on firmware version Y in most cases.
• Periodically verify the backup by booting the SD card on a PC and inspecting the directory \Storage Card\Simatic.HMI\Backup. The folder should contain a valid project.rdb or firmware-named image, not a zero-byte file.
• Avoid SD-to-microSD adapters in the MP277 slot; the slot is sized for full-size SD and the adapter can lift the card out of the contact plane, producing intermittent read errors that masquerade as a corrupt image.

Factory Reset Limitations on MP277

The MP277 10" Touch does not implement a true "factory reset" button sequence the way the MP 377 and Comfort Panels do (such as the "Select + Power" recovery). The only sanctioned factory reset is the ProSave OS update with the "Reset to factory settings" option, which is what Method 2 above accomplishes. If ProSave cannot communicate with the panel over Ethernet, the PC/PPI multimaster cable is the only remaining path; the panel cannot be force-erased by holding buttons during boot.

Troubleshooting Matrix

FAQ