Resolving PCS7 V8.1 Module Driver Compilation Error

The module driver compilation error in SIMATIC PCS 7 V8.1 manifests as E: Abort due to an internal error. The control files may be inconsistent. during the Generate Module Driver phase. This article documents the field-verified recovery procedure, root cause analysis, and preventive checks using official Siemens tooling.

1. Problem Description

When invoking the menu sequence Options → Charts → Generate Module Drivers in SIMATIC Manager, the CFC/SFC compiler aborts with the following diagnostic block in the compile log:

Generate module driver for Extra_Prj\AS_Extra\Extra_CPU410-5H\Extra_Program\ of 11/26/2021 11:36:10 AM.
E: Abort due to an internal error. The control files may be inconsistent.
>>>Due to the previous error(s), creation of module drivers was aborted<<<

The error appears after a project reorganization that initially reported success, but left internal cross-references between S7 programs, NetPro connection data, and the S7-400 station inconsistent. Subsequent module driver generation then references non-existent or duplicate block instances and aborts.

1.1 Affected Components

2. Root Cause Analysis

The internal error / inconsistent control files condition has three primary root causes, ranked by frequency observed in field reports:

1. Project integrity drift between HW Config, NetPro, and the CFC/SCL source container after a partial reorganization. The driver generator cross-validates module-type information against HW Config; a stale link produces an unrecoverable abort.
2. Stale PCS 7 Basis Library types: After a PCS 7 upgrade or Service Pack application, the APL block types in the project remain at the previous revision. The Update Block Type tool then detects a revision mismatch and silently drops the link.
3. Orphaned connection data: S7-Connection Partner IDs lost during project split/merge leave NetPro with half-defined endpoints. Importers reject these with system error 256:39.

2.1 Driver and Diagnostics Block Concept

The RACK and MODULE driver blocks are generated from the PCS 7 Basis Library for every rack and signal module configured in HW Config. The MOD_D1 / MOD_D2 diagnostics blocks detect faults, evaluate them, and forward a process control message to the OS via the PCS 7 Message mechanism. When the Generate Module Drivers function cannot resolve the module type references, it cannot instantiate these blocks, hence the abort.

For deeper reference on the driver/diagnostic block concept, see the Siemens manual Drivers, parameters, diagnostics messages and address space — Concept of the driver and diagnostics blocks.

3. Preconditions and Tooling

• SIMATIC PCS 7 V8.1 SPx (or V8.2) with the matching PCS 7 Basis Library installed via the PCS 7 Setup.
• Full read/write file permission on the project directory; project must not be opened concurrently by another SIMATIC Manager session.
• Backup of the original multi-project archive (.zip) before destructive steps.
• Reference and configuration files generated by NetPro export (xxx_Prj.cfg, AS_xxx.cfg).

4. Solution Procedure

4.1 Method A — Update Block Types from PCS 7 Basis Library (Quick Path)

This is the fastest recovery if the project was reorganized after a PCS 7 Service Pack upgrade but not yet re-linked to the new APL revisions.

1. Close all open projects in SIMATIC Manager.
2. Choose File → Open → Library and load the PCS 7 Basis Library matching the installed PCS 7 version.
3. In the project tree, select the S7 program folder of the affected AS station.
4. Navigate to Options → Charts → Update Block Type.
5. In the dialog, select the affected S7 program(s) and confirm with OK.
6. After successful update, run Options → Charts → Generate Module Drivers again.

4.2 Method B — NetPro Export / Import with Project Re-Housing (Definitive Path)

Use this method when the project reorganization left cross-references broken beyond what Update Block Type can repair.

Step 1 — Initial full compile without module drivers

1. In SIMATIC Manager, select the multi-project and run Options → Charts → Generate Module Drivers with the option to skip module driver generation (or compile SFC/CFC charts only).
2. Capture the log file to identify which AS station fails first.

Step 2 — NetPro export

1. Open NetPro for the affected project.
2. Select Edit → Export.
3. Specify the reference file as <ProjectName>_Prj.cfg.
4. Specify the station configuration file as AS_<StationName>.cfg.
5. Enable all checkbox options in the export dialog.
6. Confirm and save the .cfg files to a working directory.

Step 3 — Create an empty host project

1. Use File → New Project to create a fresh PCS 7 project named, e.g., Recover_Empty.
2. Open Project → Object Properties on the new project, switch the Use property from "As PCS 7" to "As STEP 7" temporarily. This disables PCS 7-specific type checks during paste operations.

Step 4 — Move S7-Program and S7-400 station

1. In the original project, cut the S7-Program folder from the CPU.
2. Paste it directly under the new empty project root (do not paste inside a station yet).
3. Now cut the entire S7-400 Station from the original project.
4. Paste it into the empty project. Cut/paste avoids the warnings and orphaned objects produced by delete-then-reinsert.

Step 5 — NetPro reimport

1. Open NetPro in the new project and choose Edit → Import.
2. Select the reference file <ProjectName>_Prj.cfg.
3. Several 256:39 "System-internal error" messages will appear; these are expected.
4. After import, the S7-Connection Partner ID fields on all connections will be empty.

Step 6 — Restore Partner IDs via Merge Connection

1. For every other project in the multi-project that holds an active S7 connection to this AS, open its NetPro.
2. Select exactly one S7-Connection belonging to the affected AS.
3. Choose Edit → Merge Connection. This regenerates both the local ID and the Partner ID.
4. Repeat for every other peer project.

Step 7 — Compile and restore PCS 7 type

1. In the new project, run NetPro → Compile.
2. Re-insert the S7-Program folder into the new S7-400 Station (cut/paste back into the station hierarchy).
3. Open HW Config and Station → Compile (or Ctrl+F7).
4. Re-compile NetPro.
5. Switch the project Use property back from "As STEP 7" to "As PCS 7".
6. Open the CPU and run Charts → Check Consistency → Charts as Program.
7. Finally, run Options → Compile Entire with both the Module Driver and SCL Compiler options enabled (the latter only if SCL sources are present).

5. Verification

After running the full compile, confirm the following success criteria:

6. Troubleshooting Matrix

7. Preventive Maintenance

• Always archive before reorganization. Use File → Archive to produce a compressed .zip with full multi-project integrity.
• Document the PCS 7 Service Pack level on each AS station. After every SP upgrade, run Update Block Type across the entire multi-project before generating module drivers.
• Keep a peer project map. For every S7-Connection across projects, record which project owns the active connection end, so the Merge Connection step is performed from the correct side.
• Verify NetPro after every project split. A split that loses Partner IDs is the most common cause of the 256:39 import error.
• Schedule quarterly consistency runs. Charts → Check Consistency → Charts as Program detects drift between HW Config and CFC before it surfaces as a driver compile failure.

8. Field-Proven Caveats

• The cut/paste method for moving S7-400 stations is preferred over delete/re-insert: the latter creates an Unreferenced object marker in the multi-project tree that requires manual cleanup.
• The Merge Connection menu item in NetPro must be invoked from a project that already contains a partial connection to the peer; otherwise NetPro has nothing to merge and silently exits.
• Running Generate Module Drivers on a project still set to "As STEP 7" is unsupported and will produce a different error (PCS 7 type library not loaded); always restore the Use property before this step.
• Driver blocks generated for redundant AS 410-5H stations must be compiled on both sides (AS1 and AS2); a single-side compile will produce matching but inconsistent block timestamps.

9. Related Standards and References

The PCS 7 driver generation procedure is documented in the SIMATIC PCS 7 Engineering System manual, section Generating Driver Blocks. The diagnostics block concept follows the IEC 61131-3 function block conventions, and the process-control messaging layer conforms to the PCS 7 OS message catalog specification. Consult the Siemens Industry Online Support portal for the latest Service Pack readme files, which list the APL block revisions included with each PCS 7 release.

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