TP177B 6" DP Factory Reset: PPI MM Cables and ProSave Steps

TP177B 6" DP Factory Reset: Required PPI Multi-Master Cables and ProSave Procedure

The Siemens SIMATIC TP177B 6" DP (mono STN, catalog suffix often abbreviated MSTN) is one of the most common mid-size panels in the SIMATIC HMI generation that bridged the WinCC flexible and early TIA Portal eras. Operators and commissioning engineers routinely need to return the panel to factory defaults when a unit is redeployed, when a project password is lost, when the image has been corrupted by an aborted OS update, or when the panel has been pulled from a decommissioned machine and must be repurposed for a new line.

Unlike the larger MP/TP Comfort panels, the TP177B 6" DP does not expose a true "Reset to factory" entry inside the on-board HMI loader. A PC running ProSave (the Siemens service tool that ships with WinCC flexible 2007/2008 SP2/SP3 and with the TIA Portal HMI option) is required. The non-obvious part is that not every ProSave cable works for the factory-reset function — Ethernet/PN, standard USB, and SD card are documented alternatives for OS update and Backup/Restore, but the Factory Reset operation is restricted to a specific family of PPI Multi-Master cables. This reference documents the exact cable set, why the restrictions exist, and a complete, field-verified procedure for performing the reset on a TP177B 6" DP panel.

1. Problem Statement: "I Need a Factory Reset but Have No PPI Cable"

The typical field scenario is:

• A maintenance technician has a TP177B 6" DP (mono STN) on the bench.
• ProSave is installed and the PC has a free USB or RS232 port.
• The technician does not have a Siemens PPI cable, but does have a generic USB-A to mini-USB cable, an SD card, or an Ethernet patch lead to the panel's PN port.
• The expectation is that one of those will let them trigger a factory reset from inside ProSave.

This expectation is reasonable — ProSave's first tab does list every available channel for the device, and on the larger MP277/TP277 panels ProSave will indeed let you perform a factory reset over Ethernet. On the TP177B 6" DP, however, the Reset to Factory Settings entry in ProSave is hard-gated to two specific cable part numbers. The OS Update and Backup/Restore tabs in the same ProSave dialog will still accept Ethernet/USB/serial connections, which is the source of the common field mis-assumption that "any channel listed in ProSave will work."

2. Affected Hardware and Firmware Generations

The constraint documented here applies to the TP177B 6" generation built around the X86/ARM HMI controller used in the 177-series. Variants known to be affected by the PPI-MM restriction:

All of the above share the same ProSave back-end, so the cable restriction observed on the 6" DP mono applies to its 4" and color siblings as well. The 177B DP-only units (no PN port) and the 177B PN/DP units are treated identically by ProSave for this operation.

3. Why USB, SD, and Ethernet Will Not Do a Factory Reset

The factory-reset routine on the TP177B family is not a "wipe the flash and reload defaults" function that can be served from any storage channel. It is implemented as a low-level service command that is only accepted over the legacy PPI Multi-Master link. The reasons are rooted in the panel boot loader:

1. Boot loader handshake. The TP177B boot loader (the same one used by the S7-200 PPI slaves) expects a specific PPI Multi-Master framing and a service-level challenge. A plain RS232 link or a plain USB-CDC link does not emit that framing.
2. No Ethernet / PN path in the boot loader. The PN interface is not active until the runtime image is at least partially loaded. The factory-reset routine must execute before that, so PN cannot be the carrier.
3. No SD/USB storage path. The TP177B does not have an SD slot or a host-mode USB port that the boot loader can mount. Storage-based recovery is not part of the 177B boot model — it was introduced with the Comfort line.
4. Restricted ProSave backend. ProSave's "Reset to Factory Settings" tab hard-codes the two PPI MM cable part numbers; passing any other connection type causes the button to be greyed out or to return error "Operation not supported on the selected device/channel."

4. Required Cables — The Two PPI Multi-Master Options

Only the two Siemens PPI Multi-Master cables listed below will trigger a factory reset on a TP177B. Both are catalog-numbered, both carry a Siemens-branded adapter, and both implement the PPI MM protocol on the host side.

For the USB-PPI MM (6ES7 901-3DB30-0XA0) cable, install the Siemens driver that ships with WinCC flexible or the standalone driver package from the Siemens support site. The driver presents the cable as a virtual COM port. ProSave must be configured to talk to that specific COM port.

5. Installing ProSave and Preparing the PC

1. Install WinCC flexible 2007 SP3 or WinCC flexible 2008 SP2/SP3 (the version you used to create the project). The TP177B image is signed against the WinCC flexible 2007/2008 ProSave; TIA Portal's "Reset to factory settings" entry is disabled for legacy 177B devices.
2. Confirm ProSave is on disk at C:\Program Files\Siemens\Automation\WinCC flexible\ProSave.exe or in the Start menu under Siemens Automation > SIMATIC > ProSave.
3. Plug the PPI MM cable into a free PC port. For the USB variant, let Windows enumerate the VCP and note the COM number (Device Manager > Ports).
4. Launch ProSave. The left-hand device tree should show TP177B 6" mono STN (or whichever variant is wired). Select it.
5. In the Connection drop-down on the right, choose RS232 PPI / USB PPI Multi-Master as appropriate, and select the COM port assigned to the cable.
6. Set the panel's IF1B baud to 19,200 bit/s — the default ProSave rate. Higher rates (187.5 k, 1.5 M) are valid for runtime project transfer but are not accepted by the factory-reset service handler.

6. Step-by-Step Factory Reset Procedure

1. Power up the TP177B. Allow the panel to reach the main screen (either the WinCC flexible project screen or the "No image" white screen if the image is corrupted — both are acceptable). The factory reset does not require a working image.
2. Connect the PPI MM cable from the PC to the TP177B's IF1B port (the RJ45 jack on the bottom). The panel must remain powered for the entire operation.
3. Open ProSave and select the TP177B 6" device in the tree. Choose the cable and COM port as configured above.
4. Click OK in the connection dialog. ProSave performs a PPI MM handshake with the panel. You should see a "Connection established to TP177B 6" message; if you get "Cannot establish connection", re-check the cable MLFB, the COM port, and that no other tool (Step 7 Micro/Win, TIA Portal, etc.) is holding the COM port open.
5. Open the "Reset to factory settings" tab. This tab is only visible for devices that support the operation. It is hidden for the S7-1200/1500 Comfort panels, for example, which use a different reset path.
6. Click "Reset to factory settings." ProSave prompts for confirmation: the panel will be put into a clean, unconfigured state; the project, recipes, and passwords will be lost.
7. Click Yes. The panel's RUN LED will flash or go out briefly, and the display will go black for 15–40 seconds while the boot loader erases and reinitializes the internal flash.
8. When ProSave reports "Reset to factory settings successfully completed," the panel will reboot. The first boot after a factory reset lands on the white "No image" screen with the transfer icon, ready to accept a fresh image from ProSave or from a CF/USB stick on supporting models.
9. Close the connection in ProSave and disconnect the cable.

7. What About the Other ProSave Tabs? (OS Update / Backup / Restore)

ProSave exposes three service-level operations, and only one of them is cable-restricted. The following matrix is field-verified for the TP177B 6" DP (mono STN):

The key field takeaway: factory reset is a PPI-MM-only function, but a recovery workflow that uses OS Update and Backup/Restore does not require a PPI cable at all. In many cases, an image reload over Ethernet achieves the same practical outcome as a factory reset for an unbootable or misconfigured panel.

8. OS Update via Ethernet — The Practical Alternative

If the panel can still reach the WinCC flexible "Transfer" dialog (i.e., it boots far enough to show the white transfer screen with the arrow icon), an OS Update over Ethernet will completely re-image the panel and is, in most cases, the preferred way to recover a TP177B:

1. Configure the PC's Ethernet adapter to a static address in the panel's default subnet (the TP177B ships at 192.168.0.1; set the PC to 192.168.0.2 / 255.255.255.0).
2. Connect a patch cable between the PC and the TP177B's PN port (or through a switch).
3. Open ProSave, select the TP177B, set Connection = Ethernet (PN), enter the panel's IP address.
4. Open the OS Update tab. Browse to the image file (the .img shipped with WinCC flexible 2007/2008, e.g. TP177B_6__Mono_STN_V14.0.0.0.img).
5. Click Update OS. ProSave pushes the image over Ethernet, the panel reboots twice, and lands on the fresh "No image" screen.

An OS Update erases the project, recipes, and passwords, and re-establishes the default image — functionally equivalent to a factory reset for almost all field cases. The only scenario where a true factory reset is required is when the boot loader image itself is suspect and a full re-flash of the service partition is necessary; that is the precise case the PPI-MM path exists for.

9. Recovery via the HMI Loader (When ProSave Cannot Connect)

If the panel is in a hard fault state (no display, stuck at the loader, or continuously rebooting), the HMI Loader can sometimes be reached by holding a specific touch area during power-up:

1. Power off the panel.
2. Power on, and within the first 5 seconds, press and hold the upper-left corner of the touch screen.
3. The HMI Loader menu appears with options for Transfer, Start, Info/Diagnostic, and (on some images) Reset to factory.

The TP177B 6" DP (mono STN) is one of the panels where the Reset to factory entry in the loader is either absent or disabled on the standard image. If it is present, it will perform the same low-level reset as the ProSave path; if it is absent, you must use ProSave over PPI MM.

10. Verification — Confirming the Reset Succeeded

1. Power-cycle the panel. The first boot after a successful factory reset shows the "No image" white screen with the transfer icon in the top-right — this is the canonical "factory clean" state.
2. From ProSave, perform a Read OS version via Ethernet or PPI MM. The reply should be the default image version (typically V14.0.0.0 or later, depending on what was installed at the factory), and the project version should be 0.0.0 / empty.
3. Attempt a project transfer of a known-good compiled WinCC flexible project. The transfer should complete without a password prompt, confirming that the HMI transfer password has been cleared.
4. Check the panel's IP address is back to the default (192.168.0.1) and that the PN/DP interface settings have been returned to their defaults (PN: enabled, DHCP: off; DP: address 1, baud auto-detect).
5. Touch each of the soft keys and the touch area: input response should be immediate and there should be no project-side alarms — both are indicators that the runtime has been wiped clean.

11. Troubleshooting Matrix

12. Related Manuals and Official Documentation

• Siemens Support FAQ — "Reset to factory settings for TP/OP/MP panels": support.industry.siemens.com — entry ID 19701610
• SIMATIC HMI TP177B Device Manual (WinCC flexible 2007): Siemens Industry Online Support — search for 6AV6 642-0BA11
• WinCC flexible 2008 SP3 — ProSave user documentation (installed under Documentation\English\ProSave_e.pdf)
• Siemens USB-PPI Multi-Master Cable driver package — available in the Downloads area of the Siemens support portal, search term "USB PPI Multi-Master driver".