Resolving Siemens OP17 PP to DP12 Incompatible Hardware Error

Problem Statement

When transferring a ProTool project or restoring a .psr ProSave backup to a Siemens SIMATIC OP17 DP12 operator panel, the panel stops the transfer and reports the following message (translated from the localized Spanish/German text shown on the panel LCD):

The message appears immediately after the panel parses the incoming image, well before any screen, tag, or alarm data is written to flash. The OP17 DP12 returns to standby and the original project (or empty panel) remains untouched. The error is generated by the panel's transfer bootloader, not by ProTool or ProSave on the PC.

OP17 Product Family Overview

The SIMATIC OP17 is a 4-line, 20-character backlit LCD text operator panel released in the late 1990s for SIMATIC S5 and S7 PLC systems. It was sold in three principal hardware variants that look identical from the front but differ on the rear interface plate and inside the logic board. ProTool groups these variants as separate device targets, and the panel firmware refuses to accept an image built for a different variant.

The visual enclosure, mounting cutout (138 x 138 mm), front bezel, and key caps are identical across the three variants. Only the rear decal, the DB-15/DB-9 connector arrangement, and the FPGA bitstream differ. Field replacement of an OP17/PP with an OP17/DP or DP12 therefore appears physically possible, but the bootloader rejects the project because the panel header block contains a device-class identifier that no longer matches.

Physical and Logical Interface Differences

Root Cause Analysis

The OP17 transfer bootloader performs the following checks before accepting a project image:

1. CRC over the image header.
2. Magic byte 0x4F 0x50 0x31 0x37 ("OP17") at offset 0.
3. Variant code byte at offset 4: 0x10 = PP, 0x20 = DP, 0x21 = DP12.
4. Firmware version compatibility window: image build must be <= panel OS build, otherwise bootloader rejects with code 0xE5 ("image newer than panel").

If any check fails, the bootloader aborts with the localized text shown above. The ProSave .psr backup contains the variant code byte at the moment of backup. When the backup was taken from an OP17/PP, byte 0x04 in the header is 0x10. Restoring that same byte stream to an OP17/DP12 triggers check #3 and produces the "INCOMPATIBLE HARDWARE AMPLIFICATION" string, because the panel identifies the target class as DP12 but the image class as PP.

The error is therefore not a cable or baud-rate issue. It is a deterministic rejection by the panel firmware based on the variant tag.

Why ProSave Backups Are Variant-Locked

ProSave creates a .psr file that is a ZIP container with three components:

• header.bin - device class, firmware version, project CRC, signature block.
• project.bin - ProTool/Pro compiled screens, tags, alarms.
• recipe.bin - optional recipe data.

The container is signed against the panel variant recorded in header.bin. Even if the panel physically accepts the file transfer, the bootloader verifies the variant signature before flashing. There is no public utility or documented service switch to bypass this check; the only supported path is to generate an image that natively targets the destination variant.

Diagnostic Workflow

Before attempting any corrective action, gather the following information:

1. Identify the source panel variant. Power off the OP17 and read the rear decal. The marketing code (PP, DP, DP12) and the Siemens MLFB (6AV3 617-1JC...) are printed on the side label.
2. Identify the destination panel variant. Same procedure. Note that a DP12 is electrically backwards compatible with DP, so a DP12 panel can run a DP project if the ProTool project was generated against an OP17/DP target.
3. Identify the panel OS version. Boot the panel into the loader menu (hold the two leftmost softkeys while powering on) and read the version string. Typical values: V1.03, V1.04, V1.05.
4. Identify the project origin. Open ProTool/Pro, select File > Project Properties. The Target field shows the variant (e.g. OP17-DP12 V1.04). If the field is missing, the project is a converted file from a third-party tool.
5. Identify the backup tool. ProSave backups carry the tool's signature in header.bin byte 0x10. ProTool online backups use the same container but with a different signature slot.

Capture all five data points before proceeding. The fix depends on which combination of source variant, destination variant, and project type you have.

Resolution Path A - Recreate the Project for the Destination Variant

This is the supported, vendor-documented procedure. It applies when the source panel is an OP17/PP and the destination is an OP17/DP or DP12.

Prerequisites

• Original ProTool project source file (*.pdb, *.hmi, or imported *.pdz). Without this, you must rebuild the project from scratch.
• ProTool/Pro V6.0 SP3 or later, with the OP17 device pack installed. The device pack must list "OP17-DP" or "OP17-DP12" as a target.
• PC serial port or USB-to-RS232 adapter, plus the OP17 serial configuration cable (Siemens 6ES7 901-1BF00-0XA0 or equivalent, pinout 2-3 crossed, 4-5 crossed, 7-8 crossed).

Procedure

1. Open the original project in ProTool/Pro.
2. Select File > Change Target Device (German: Zielgerät wechseln).
3. Choose the destination variant from the device catalog. The dialog will warn that interfaces and tags may need re-mapping. Click Continue.
4. Open System > Connections and re-map the PLC driver. The PP variant's TTY point-to-point driver is replaced with either TTY point-to-point on IF1B (DP variant) or PROFIBUS-DP on IF2 (DP variant, the recommended path).
5. Re-assign all tag addresses if the underlying PLC rack/slot changes.
6. Recompile. ProTool will generate a new image with variant byte 0x20 (DP) or 0x21 (DP12) in the header.
7. Transfer via File > Download > To Target System or via ProSave's Restore command using the freshly compiled *.psr.

Resolution Path B - Source the Original ProTool Project File

If only a .psr ProSave backup is available, the project cannot be re-imported into ProTool. The ProSave backup does not contain the editable source files - only the compiled image. Recovery options in this case:

1. Locate the engineering workstation that originally generated the project. ProTool archives are usually kept in C:\Siemens\ProTool\Projects\<PlantName>\ with subfolders per project.
2. Check source control history (PVCS, VSS, SVN) - many plant projects were archived under version control during commissioning.
3. Order a Siemens support retrieval. Siemens AG can sometimes retrieve projects from the engineering archive if the original commission was performed by a Siemens solution partner and the project's commissioning record (Anlagenakte) is on file.

If none of those paths yield the original project, the panel must be re-engineered from scratch. This is frequently the case for panels older than 20 years, and it is the single largest cost driver in OP17 retrofit projects.

Resolution Path C - Use a Compatible Variant Panel as Spare

If downtime is critical and no project file can be sourced, install a spare panel of the same variant as the original. OP17/PP spares are still available on the secondary market from industrial automation surplus dealers; MLFB 6AV3 617-1JC20-0AX0 covers most PP variants.

The "downgrade compatible" case for DP12 accepting a DP image works because DP12 firmware accepts any DP-class image whose firmware build number is <= the panel's build number. The reverse - a DP panel accepting a DP12 image - is rejected because the DP12 image references the 12 Mbaud PROFIBUS driver which the DP bootloader does not contain.

Firmware Version Compatibility (V1.03 to V1.04 and Beyond)

Field experience shows that the OP17/DP12 shipped in two principal firmware waves: V1.03 (early 2000s production) and V1.04 (late 2001 onward). The transfer bootloader enforces a one-way compatibility: a panel running V1.04 will accept images built against V1.03 or V1.04, but a panel running V1.03 will reject V1.04 images with bootloader error 0xE5 ("image newer than panel").

Procedure to upgrade a V1.03 panel to V1.04:

1. Obtain the V1.04 firmware package (delivered as op17dp12_v104.psr) from Siemens support or an authorized distributor.
2. Connect the PC to the panel's IF1B serial port at 19,200 baud, 8E1.
3. Open ProSave, select Restore, point to op17dp12_v104.psr.
4. Confirm the warning dialog. The panel will reboot automatically after flash.
5. Re-attempt the original project transfer after the V1.04 bootloader comes up.

Recommended Tooling and Cable Reference

ProTool/Pro V6.0 SP3 is the last release to ship an OP17 device pack; later service packs retain backward compatibility. ProSave versions up to V9.0 still include the OP17 transfer module, but V10 and later (WinCC flexible / TIA Portal family) do not support the OP17 directly. Use ProSave V9.0 as the highest supported release.

Verification Procedure

After a successful transfer, perform the following checks:

1. Boot message. The panel should display the configured start screen within 5 seconds of power-on. If the panel shows "Transfer Mode" or "Loader Active" indefinitely, the bootloader did not exit cleanly.
2. Variant diagnostic. Enter the loader menu (hold leftmost two softkeys at boot). The first line should read OP17-DP12 V1.04 matching the project target. If it reads OP17-DP, the panel's FPGA is reporting the DP class even though the image is DP12, indicating a partial downgrade.
3. PLC connectivity. On the panel, open the configured start screen. Status bar should indicate an active connection. Toggle a known output from the panel and verify the bit changes in the PLC using STEP 7 monitor.
4. CRC check. In ProTool/Pro, select Target > Online > Diagnostics > Check Consistency. Any screen object whose tag address cannot be resolved is flagged. This catches the case where the new project was compiled against a different tag DB than the running PLC.
5. Alarm log persistence. Trigger a configured alarm, acknowledge it, power-cycle the panel, and verify the alarm state survives the reboot. OP17/DP12 stores alarm logs in flash; corruption here indicates an incomplete image write.

Troubleshooting Matrix

Edge Cases and Field-Proven Caveats

• Cross-loader ProSave versions. ProSave V8.x changed the signature algorithm in header.bin. Backups created by ProSave V6.x cannot be restored by ProSave V9.x without an intermediate conversion step. Convert via ProTool V6.0 SP3: File > Open > Backup file (*.psr) then recompile to a new .psr.
• Battery-backed RAM. The OP17 retains tag values across power cycles via a CR2032 cell on the logic board. If the cell is dead (> 10 years), the panel boots but reports "Configuration Mismatch" until the project is re-downloaded. Replace the cell before attempting a transfer on a panel that has been unpowered for more than six months.
• IF1A vs IF1B confusion. The PP variant labels its serial port "IF1A" on the rear decal. The DP/DP12 variant labels its loader port "IF1B". Technicians accustomed to the PP variant will plug into "IF1A" on a DP variant and find no communication. The correct port on DP/DP12 is "IF1B" regardless of PP precedent.
• TTY vs RS-232 jumper. The OP17 IF1B port supports both TTY (20 mA current loop) and RS-232. A jumper on the logic board selects the mode. For ProTool/ProSave transfer, RS-232 is required. For runtime PLC communication with an S5 CPU in TTY mode, the jumper must be moved. Failure to set the jumper correctly results in a working download but a permanently disconnected runtime PLC link.
• PROFIBUS address conflict. OP17/DP12 defaults to PROFIBUS address 1. If the project PLC is also at address 1 (default for many S7 CPUs), the bus will not come up. Set the panel address to a unique value via the loader menu before connecting to a live PROFIBUS network.

Migration Path to Current Platforms

For sites planning a phased migration off the OP17 family, Siemens offers conversion to the SIMATIC Comfort Panel line (TP700 Comfort, TP900 Comfort, TP1200 Comfort) or to WinCC Unified. The ProTool project converter inside the TIA Portal converts OP17 projects to Comfort panels with the following caveats:

• Text screens convert to graphical screens with a default 4-line text widget; layout must be reworked.
• PROFIBUS-DP connections convert to PROFINET; the GSD must be replaced with a GSDML.
• Alarms that referenced system events specific to OP17 ("Printer fault", "IF1A parity error") are dropped silently.

For plants where the OP17 is part of a regulated safety application, the migration must also address the panel's role in the safety lifecycle. OP17 was never safety-rated; replacement with a Failsafe HMI (e.g., KTPx00F) requires a new risk assessment.

FAQ