Recovering ProTool from STEP 7 and Migrating PC477B

Overview: PC477B Crash Recovery and Standalone Migration

The SIMATIC Panel PC 477B is a compact, fanless industrial PC based on the Intel Celeron M platform, designed for HMI/SCADA duties directly at the machine. When the on-board CompactFlash, HDD, or motherboard of a PC477B fails, the machine line is at risk because the HMI runtime is bound to that specific hardware. Operators historically have two recovery paths: replace the PC477B with an identical refurbished unit, or migrate the HMI to a standard industrial PC. The second path is the focus of this article.

PC477B systems shipped before 2010 were typically delivered with ProTool V6.0 SP1 or ProTool V6.0 SP3 for the HMI runtime and STEP 7 V5.x for the PLC/CP programming environment. ProTool projects are commonly integrated into the STEP 7 project, which means the HMI source files are embedded in the S7 project container. Recovering those files from a STEP 7 backup is the first step of any standalone migration.

Problem Details: Failure Symptoms

Three failure modes drive a typical PC477B-to-standalone migration:

1. Hardware failure – CompactFlash wear, HDD SMART error, or motherboard capacitor failure preventing POST.
2. OS corruption – Windows XP boots into safe mode or fails with a STOP 0x7B INACCESSIBLE_BOOT_DEVICE after a power event.
3. Runtime DLL error – ProTool Runtime starts, then aborts with OID 5 == OID_POB_CTDRIVER_MANAGER, preventing the HMI from communicating with the S7-CPU via MPI/DP.

The OID_POB_CTDRIVER_MANAGER error is raised by the ProTool/ProSave communication layer (POB = ProTool Object Base) when the internal driver manager cannot initialise the CP5611/CP5711/CP5512 driver DLL. The runtime launches the GUI but cannot bind a logical connection to the PLC, so the project loads in offline mode and tags remain static.

Root Cause Analysis

The OID 5 fault is typically caused by one of the following root causes:

The PC477B itself has a dedicated onboard MPI/DP interface (CP 5611-compatible, ASIC-based) that is wired directly to the PROFIBUS connector on the rear of the unit. A standalone PC does not have this onboard CP, which is why an additional MPI communication processor is mandatory.

Solution Path 1: Extract ProTool Project from STEP 7 Container

When the ProTool project is integrated into the STEP 7 project, the HMI files are stored as a binary block within the S7 program. The project can be extracted on any PC that has the matching ProTool version installed:

1. Install STEP 7 V5.5 plus the matching ProTool V6.0 SP3 (or the SP level that matches the crashed PC) on the maintenance PC. The ProTool V6.0 SP3 service pack and base ProTool/ProSave FAQ describe the correct installation order.
2. Open the STEP 7 project (the .s7p file) in SIMATIC Manager.
3. Right-click the HMI station (e.g. PC477B_HMI) in the project tree and select Object Properties.
4. In the Integrated Project tab, change the HMI type from ProTool/Pro to ProTool V6.0 if it is greyed out, and confirm the source path.
5. Right-click the HMI station and select Retrieve ProTool Project (or Start ProTool). ProTool launches and opens the embedded .pdb database directly from the STEP 7 container.
6. Once open in ProTool, immediately save the project as a standalone .pdb file using File > Save As. This breaks the STEP 7 binding and produces a portable project file.

Solution Path 2: Install ProTool Runtime on the Standalone PC

The standalone PC hardware must meet the following minimum configuration to host ProTool Runtime:

Installation sequence:

1. Apply Windows XP SP2 or SP3. Disable DEP for the proagent.exe and Wc32.exe processes via System > Advanced > Performance Settings > Data Execution Prevention.
2. Install SIMATIC NET PC Software (version corresponding to the MPI CP) before installing ProTool. This provides the S7ONLINE access point and the POBDriver service.
3. Insert the CP5711 (USB) or CP5611 (PCI) and confirm the driver loads without yellow bangs in Device Manager.
4. Install ProTool/Pro V6.0 from the original DVD, then apply the matching SP3 over the top. Reboot when prompted.
5. Install ProTool Runtime from the same media. The installer places ProRun.exe and the POB service in C:\Program Files\Siemens\ProTool.
6. Open SET PG/PC Interface and configure the S7ONLINE access point to point at the installed CP (CP5711 MPI or CP5611 MPI).

Solution Path 3: Resolve OID 5 (OID_POB_CTDRIVER_MANAGER)

After installing SIMATIC NET, ProTool, and the runtime, perform the following corrective steps if the OID 5 error persists:

1. Verify the POBDriver service is registered and started: sc query POBDriver from a command prompt. If absent, run C:\Program Files\Siemens\ProTool\Setup\POBInst.exe /reg.
2. Open SET PG/PC Interface (32-bit). Confirm the S7ONLINE access point is mapped to a CP, not to None or PC Internal.
3. Run ProSave with administrator rights. The utility is located at C:\Program Files\Siemens\ProTool\ProSave.exe.
4. Reinstall the matching ProTool SP3 over the existing install. A common cause of OID 5 is a partial SP install that left the driver manager DLL newer than the wrapper.
5. Check registry key HKLM\SOFTWARE\Siemens\Automation\ProTool\RT\DriverManager. The value ActiveDriver should reference the SIMATIC NET path. If it is empty, the runtime cannot find the CP DLL and the OID 5 error is raised on first connect.
6. As a last resort, uninstall ProTool, SIMATIC NET, and the CP driver; reboot; reinstall in the order SIMATIC NET → ProTool V6.0 → ProTool SP3 → ProTool Runtime.

Hardware: MPI Communication Processor Selection

The PC477B has an integrated MPI/DP interface on the rear panel. A standalone PC has no such interface, so an external CP is required. The two recommended MPI/DP processors are:

Cabling and Bus Termination

The PC477B normally sits at one end of the MPI bus. To preserve the existing bus topology:

1. Use a PROFIBUS DP cable (purple, twisted pair, shielded) with a 9-pin D-sub connector on the CP end and free wire ends or a second connector on the PLC end.
2. Terminate the standalone PC end of the segment with a PROFIBUS terminator (220 Ω between pins 3 and 8, 390 Ω from pin 3 to pin 5 and pin 8 to pin 5) if the PC477B was the bus terminator in the original machine.
3. Set the CP address to the same MPI address that the original PC477B had. Default for ProTool Runtime is MPI address 1; verify in SET PG/PC Interface → Properties → Address.
4. Set the bus baud rate to match the S7-CPU: 187.5 kbit/s is the standard MPI default; 1.5 Mbit/s and 12 Mbit/s are also valid if the CPU supports them.

Commissioning Procedure: Standalone PC + ProTool Runtime

1. Power up the standalone PC; confirm Windows XP boots cleanly.
2. Verify the MPI CP in Device Manager: status This device is working properly.
3. Run SET PG/PC Interface; set S7ONLINE to the installed CP; click Diagnostics → Test. The test must report OK on the first two passes (own address and bus scan).
4. Launch ProTool Runtime from Start > Programs > Siemens > ProTool > ProTool Runtime, or automatically via the ProRun.exe entry in the Run key.
5. Confirm the HMI starts in online mode (process tags update) rather than offline.
6. Touch-test all function keys, alarms, and recipe screens. The ProTool project size is limited to 128 KB for the configuration plus 256 tags; runtime response should be under 200 ms per screen change on a 1 GHz class CPU.
7. Reboot three times in succession to confirm the runtime starts cleanly every time. A clean cold boot is the standard acceptance criterion for a ProTool Runtime.

Verification Checklist

Alternative: Replace the PC477B with a Refurbished Unit

If the operating environment is critical and the cost of a Windows XP SP3 license plus an industrial PC plus a CP card approaches the cost of a refurbished PC477B, the OEM-supported path is direct hardware replacement. The PC477B part numbers and safety guidelines are documented in the SIMATIC Panel PC 477B Compact Operating Instructions and the SIMATIC Panel PC 477B Operating Instructions. A refurbished unit preserves the original bus topology, the original keyboard template, and the original warranty path. Choose this option when the HMI software stack is also tied to the PC477B (for example, when WinCC flexible 2008 SP3 or a custom OPC server was installed in addition to ProTool).

Long-Term Migration Note

ProTool V6.0 reached end-of-life and is no longer serviced by Siemens. The supported successor on the same hardware footprint is WinCC flexible 2008 SP5 on Windows XP, and the modern migration target is WinCC (TIA Portal) V17 or later on Windows 10 IoT LTSC. A standalone PC running ProTool Runtime should be considered a stop-gap, with a planned upgrade to WinCC flexible or TIA Portal within one to two years. When the migration is performed, switch the MPI CP to a CP 5711 with an Ethernet gateway (e.g. PN/MPI coupler) or a native PROFINET interface, eliminating the legacy PROFIBUS cable and the legacy CP5611 driver stack.

FAQ