Restoring Siemens MP377 HMI from CF Card and USB Without WinCC

Overview

The Siemens SIMATIC MP377 Multi Panel is a Windows CE-based HMI from the 6AV6 644 product family (12" key, 12" touch, 15" touch, 19" touch). It runs a WinCC flexible Runtime that hosts a compiled project, recipes, alarm/audit logs, and the underlying CE image. The on-board backup routine in the Control Panel can write this entire image to a CompactFlash (CF) card or a USB mass-storage device, allowing a complete field restore of the panel without a PC running WinCC flexible. This is the standard workflow for shipping a pre-configured panel to a remote site, recovering a panel after storage failure, rolling a known-good configuration across a fleet, or returning an RMA unit to a working state.

The MP377's restore media must be created on a panel, not a PC. A direct file copy from a USB drive that was first written by Windows will fail because the panel expects the cluster layout and directory ordering produced by its own CE USB stack. This article documents the supported CF card path, the panel-to-panel USB path, and a disk-image workaround for sites where the media must transit PC infrastructure. The procedures follow chapter 6 of the WinCC flexible operator manual, which is published on Siemens Industry Online Support under document entry 26248558. The MP377 device manual is published under the 6AV6 644 product family on the same portal.

Prerequisites

Verify the following before starting:

• Hardware: any MP377 variant of the 6AV6 644 family. Touch and key variants are interchangeable for backup/restore because the image contains the matching CE shell.
• Firmware: WinCC flexible Runtime 2008 SP3 or later. Earlier runtime builds support backup/restore, but the on-disk format differs and a cross-version restore is not guaranteed.
• Storage media:
  • CF card: Type I or II, FAT16 or FAT32 formatted, 128 MB minimum, 8 GB practical maximum on older firmware. Industrial-grade cards (for example, Siemens 6AV6 575 series or equivalent) are recommended for vibration-prone sites.
  • USB: USB mass-storage class device, FAT16 or FAT32. exFAT is not supported. Stick to 4 GB or smaller drives on legacy firmware because the FAT32 sector size matters.
• Power: 24 VDC nominal (20.4-28.8 VDC range) per the MP377 datasheet. Allow 30 s for the panel to reach the Control Panel state.
• Personnel: any operator trained to navigate the CE Control Panel; no engineering tool required.
• For the disk-image workaround only: a Windows or Linux PC with a USB port and a sector-level imager.

Backup Architecture: What Gets Saved

A backup created from the Control Panel's Backup/Restore applet contains a complete snapshot of the panel's runtime state. Specifically, the panel writes a timestamped directory containing:

• The compiled WinCC flexible project and its companion runtime files.
• The Windows CE image and the registry hive that drives the runtime shell. This is what makes the restore possible without a PC-side install of WinCC flexible.
• Recipe data, alarm logs, and audit trail archives (if the project writes them to the standard locations).
• Operator-specific settings such as language and screen brightness.

The CE image is the most important artifact. A restore that supplies the project but no image will fail to boot on a panel that has been re-flashed or replaced. Always choose a Complete Backup unless you are certain the receiving panel already holds a matching CE image.

Step-by-Step: Backup to CF Card

The CF card path is the canonical, fully-supported restore media. The panel boots from the CF slot natively, so the restore can recover a panel that will not start its runtime.

1. Power on the MP377. Wait for the Control Panel to appear (about 30 s).
2. Insert the CF card into the slot on the back of the panel. The CE shell auto-mounts the card and a notification appears in the taskbar.
3. From the Control Panel main menu, open the Backup/Restore applet. On older firmware the applet is labeled Backup and is located under the OP/MP tab.
4. Select CF Card as the destination media.
5. Select the data set: Complete Backup (project + CE image, the default and the recommended option) or Project Only (use this only if the receiving panel already holds a matching CE image).
6. Confirm. A progress bar shows the write status. A full backup typically completes in 3-8 minutes depending on CF card speed and the size of the project and CE image.
7. When the panel prompts for safe removal, confirm and pull the card.

Repeat for each panel in the fleet. The CF cards can be shipped to the field site; the destination panel only needs the card and 24 VDC.

Step-by-Step: Restore from CF Card

1. With the panel powered, insert the CF card containing the backup.
2. Navigate to Control Panel → Backup/Restore.
3. Select the source media (CF card) and the timestamped folder matching the backup you want to load.
4. Choose Complete Restore or Project Restore as appropriate. Complete Restore is the default and recommended option for RMA recovery or fleet rollout.
5. Confirm. The panel writes the image and reboots. The first boot is longer than a normal start (60-90 s) because the CE image is rehydrated.
6. The runtime auto-launches after boot. Verify the project version in the system diagnostics screen.

Step-by-Step: USB Backup and Restore (Panel-to-Panel)

USB is faster and the media is cheaper than CF, but it is restricted to the panel-to-panel path. The procedure mirrors the CF flow.

1. Insert a USB mass-storage device in the front USB port of the source panel.
2. In Backup/Restore, select USB as the target.
3. Run the backup. The panel writes a directory of the same structure as the CF card path; the cluster ordering and timestamps are produced by the CE USB stack.
4. Physically transport the USB drive to the destination panel. Do not insert the drive into a PC, do not copy the files off, and do not reformat. A user-mode file copy onto a different USB drive breaks the layout that the MP377's restore routine expects.
5. On the destination panel, insert the same USB drive, select USB as the source, and run Restore.

Workaround: Cloning USB Media with a Disk Image

When the backup has to be emailed, replicated to many sites, or stored on a server, capture a sector-level image of the USB drive. The user-mode FAT copy breaks the layout assumption; a bit-for-bit clone preserves it.

Tools that work for this purpose:

• Linux/macOS: dd (built in)
• Windows: Win32DiskImager, USB Image Tool, or ImageUSB
• Commercial: Acronis True Image, Norton Ghost, or any sector-level disk imager

Procedure (Linux, using dd):

1. Identify the USB device with lsblk (Linux) or diskutil list (macOS). The USB drive is typically /dev/sdX on Linux.
2. Capture the image: sudo dd if=/dev/sdX of=mp377_backup.img bs=1M status=progress
3. Transfer the .img file by the method of choice (email, FTP, S3, etc.).
4. On the destination PC, insert a USB drive of equal or larger capacity.
5. Write the image: sudo dd if=mp377_backup.img of=/dev/sdY bs=1M conv=fdatasync. Replace /dev/sdY with the destination device node.
6. On the destination MP377, insert the cloned USB drive and run Restore.

Procedure (Windows, using Win32DiskImager):

1. Insert the source USB drive. Open Win32DiskImager, select the device letter, and the output filename mp377_backup.img.
2. Click Read. The image file is written sector-by-sector.
3. Transfer the .img file to the destination site.
4. Insert the destination USB drive. Open Win32DiskImager, select the .img file, and click Write.
5. Run Restore on the destination MP377.

Choosing the Right Restore Mode

The Backup/Restore applet presents three practical modes. Pick based on the use case:

Verification

After every restore, perform the following checks before releasing the panel to production:

1. Power cycle the panel. The first boot is the test; if the panel hangs at the CE splash, the CE image is corrupt and a second Complete Restore is required.
2. Confirm the runtime starts within 90 s. The WinCC flexible splash screen appears, then the project.
3. Open the project menu, navigate to system diagnostics, and verify that the project version and build timestamp match the backup you loaded.
4. If recipes were included, log in as a privileged user and verify the recipe list is populated. An empty recipe list after a Complete Restore indicates a corrupt image.
5. Trigger a screen change, acknowledge a forced alarm, and write a test value to confirm the runtime is fully responsive.
6. If the panel was re-imaged, re-apply any IP address, PROFINET device name, and time-zone settings that were not part of the backup snapshot.
7. Re-run touch calibration from the Control Panel; calibration is per-panel hardware and is not part of the backup.

Troubleshooting Matrix

Migration Note: From WinCC flexible to TIA Portal

The MP377 is a WinCC flexible platform; it is not a TIA Portal Comfort Panel. New deployments should consider the SIMATIC TP/MTP Comfort Panels, which are the modern successors and integrate with TIA Portal. Existing MP377 fleets can be maintained indefinitely with the backup/restore procedure described above. A migration to a Comfort Panel requires a TIA Portal project, not a WinCC flexible backup, so the MP377 backup is not portable across panel families. The WinCC flexible → TIA Portal migration tool can port the project, but the runtime will only load on a TIA-supported panel.

FAQ