D7-SYS CFC Memory Card Load Failure: Resolving Missing KAM001.msk Library Errors

When a D7-SYS project is downloaded to a SIMATIC S7 memory card (MMC or CF), the offline backup pipeline can abort with a missing-library fault that prevents the S7 program tree from being written to the card. The most common symptom is a dialog stating "Compile first" followed by a compiler log line such as Library KAM001 cannot be resolved or KAM001.msk not found. The root cause is almost always a version mismatch between the .a / .msk library pair shipped in the project ZIP and the installed D7-SYS service pack, and the remedy is to place the correct library pair in the appropriate sdblocks directory and re-run the compile.

This reference consolidates the field-proven diagnostic flow used by drive commissioning engineers to recover from a missing-library compile abort on a SIMATIC MMC/CF card, with explicit path tables, a .KMZ install procedure, version compatibility notes, and a verification matrix. The procedures apply to SIMATIC S7-300, S7-400, ET 200S, and SINAMICS / MASTERDRIVES applications programmed with SIMATIC S7-CFC under D7-SYS V6.x through V8.2.

1. Problem Overview

D7-SYS uses SIMATIC S7-CFC as the underlying engineering environment, with two layered compilation passes:

1. CFC/SFC chart compiler — resolves all block instances in the chart and produces the chart sources (.src) and the call structure.
2. S7 library loader — binds the chart to one or more master driver libraries (e.g. FBSGMC.A / FBSGMC.MSK) and any project-specific custom libraries (e.g. KAM001.A / KAM001.MSK) and generates the S7 program tree.

If the second pass cannot bind to a library, the compiler reports the missing file and refuses to write a valid S7 program to the target memory card. The Download to Memory Card button is disabled until the compile produces a valid S7 program tree. The fault is non-recoverable through the chart editor alone; the engineer must intervene on the disk.

The situation commonly arises in the following scenarios:

• A machine builder ships a project ZIP exported from D7-SYS V6.x and the receiving maintenance engineer installs D7-SYS V8.x on the maintenance laptop.
• The supplier delivers a .KMZ (CFC library archive) whose internal .msk was compiled against a different D7-SYS service pack than the one used to export the chart.
• The original project folder was archived without the \Global\sdblocks subfolder, leaving only the chart sources and the S7 program files on disk.
• The S7-CFC installation was upgraded in place, leaving stale .msk files in the global installation sdblocks directory.

2. Root Cause: Library Version Mismatch

A D7-SYS drive library is a paired file set:

The two files must originate from the same D7-SYS build (major.minor.servicepack, optionally with hotfix). If .a is V6.0 SP4 and .msk is V8.1, the S7-CFC loader detects a header-version mismatch in the mask and aborts the compile with "Library cannot be resolved". The same abort is produced if the .a exists but the .msk is missing entirely.

For project-specific libraries (the KAM family — Kundenanpassungsmodul / customer adaptation module — e.g. KAM001), the version stamp is even more sensitive because the mask encodes the KAM slot, the parameter list, the protocol binding, and the CRC of the parameter set. A KAM001.MSK from one drive firmware revision will not bind to a project whose drive parameters were exported from a different firmware. This is the exact failure mode observed when a supplier ships a .KMZ of the wrong version: the .a may load but the .msk is rejected, and the compiler produces a generic missing-library error rather than a precise version-mismatch warning.

3. Library File Structure and Naming

Standard D7-SYS drive libraries follow the pattern FB<family>.a / FB<family>.msk. Common family codes used in production environments:

Custom libraries follow the convention chosen by the supplier. A KAM (Kundenanpassungsmodul) is typically named KAM<index>.a and KAM<index>.msk where <index> is a three-digit decimal. The user-visible example KAM001 indicates a single customer adaptation module integrated by the machine builder. Other custom prefixes in active use include:

4. D7-SYS Compilation Log Interpretation

A typical aborted compile log reads (paths abbreviated for clarity):

=== Compile/Download statistics ===
Block list generated
S7 program : S7PROGR
Passive station handling: no
System data: from installation
Library: KAM001 (vendor: OEM)
... KAM001.msk not found in ...\Project\Global\sdblocks
   or in C:\Program Files (x86)\Siemens\Step7\s7cfc\sdblocks
Compilation aborted.

The two critical lines to extract from the log are:

1. The block family declared in the log (e.g. KAM001). This identifies the missing library pair.
2. The path in which the compiler searched. The searched path depends on the option in Options → Customize → Compile/Download.

Other useful log fields:

5. Library File Placement Directories

D7-SYS looks for .a and .msk files in one of two locations, depending on the system-data option selected in the project:

On 64-bit STEP 7 installations the path may be C:\Program Files\Siemens\Automation\Step7\s7cfc\sdblocks. Verify against the actual STEP 7 install path on the workstation. On Windows 10/11 with UAC enabled, writing into Program Files requires the editor to be launched as administrator — the CFC editor does not auto-elevate.

Both files of a pair must be present in the same directory. If only the .a is present, the compiler reports the missing .msk even though the file is in the project ZIP. Symlinks and NTFS Junctions are not supported by the S7-CFC loader — use a real copy. File attributes also matter: if either file is marked read-only (e.g. restored from a CD image), the compiler may report a write failure rather than a missing-library error.

The two options are mutually exclusive per project. Switching the option forces a full re-link; the previous .msk is no longer consulted. This is by design: a project meant to be portable across workstations should use "System data from project folder", while a workstation with a curated global library set should use "System data from installation". On a maintenance laptop, the latter is often the better choice because the global sdblocks directory can hold many versions of the same library family and the loader can pick the one matching the chart's required major version.

6. Step-by-Step Resolution Procedure

The recommended recovery sequence for an offline backup load into a memory card is:

1. Export the project ZIP from the original development laptop if you still have access to it. The ZIP must include the \Global\sdblocks folder that contains the originally compiled library pair. Use File → Archive in SIMATIC Manager with the "With S7 library references" option enabled, or in D7-SYS use Project → Export → Project archive.
2. Open the project on the maintenance laptop with the D7-SYS version that matches the original development version. This is the only reliable way to load a backup from a project ZIP. If the original version is unavailable, request it from the supplier or commission a virtual machine with the required service pack.
3. Inspect the compilation log to identify the missing library family. If the log shows KAM001, the missing pair is KAM001.a and KAM001.msk. Note the vendor field and the header version when present.
4. Choose the system-data option in Options → Customize → Compile/Download that matches your working scenario:
   • System data from installation — for workstations with a curated global library set installed by IT.
   • System data from project folder — for portable projects that must work on any laptop.
5. Place the library pair in the corresponding directory. Use Windows Explorer, copy from a command prompt, or robocopy to preserve attributes:

   REM System data from installation
   copy KAM001.a "C:\Program Files (x86)\Siemens\Step7\s7cfc\sdblocks\"
   copy KAM001.msk "C:\Program Files (x86)\Siemens\Step7\s7cfc\sdblocks\"
   
   REM System data from project folder
   copy KAM001.a "<project>\Global\sdblocks\"
   copy KAM001.msk "<project>\Global\sdblocks\"

6. Re-run the compile/download. The CFC compiler must report "0 errors, 0 warnings" and generate the S7 program files (S7PROGR.S7P, the system data blocks, and the chart sources) into the project download folder.
7. Write to the memory card using the standard SIMATIC transfer sequence:
   • Power down the PLC and remove the MMC/CF card from the CPU (CPU 314/315/317/319, ET 200S, etc.).
   • Insert the card into the programming device's PC card slot (or use a SIMATIC USB card reader such as 6ES7792-0AA00-0XA0).
   • In STEP 7 Manager, choose PLC → Download to Memory Card.
   • Select the target card slot and the S7 program tree. Confirm the overwrite prompt.
8. Re-insert the card into the CPU and perform an overall reset (MRES) before the first download. The MRES clears the RAM work memory and forces a fresh load of the S7 program from the card.

7. Working with .KMZ Library Archives

A .KMZ file is a ZIP archive that contains a D7-SYS library in compressed form. The archive bundles the .a and .msk files together with metadata so the library can be versioned and distributed. To install a .KMZ file:

1. Open D7-SYS / S7-CFC on the maintenance laptop.
2. Choose Options → Library → Install / Uninstall.
3. Browse to the .KMZ and confirm the installation. The installer extracts the files into the sdblocks directory of the current mode (installation or project).
4. Verify both files appear in the chosen directory using Windows Explorer or dir from a command prompt.
5. Restart the D7-SYS editor so the library registry is re-read. S7-CFC caches the library list at editor start.

To verify the contents of a .KMZ without installing, treat it as a ZIP and list its members:

powershell Expand-Archive -Path KAM001.kmz -DestinationPath C:\temp\kmz_inspect
dir C:\temp\kmz_inspect
type C:\temp\kmz_inspect\manifest.xml

The manifest (if present) typically records the D7-SYS version that produced the archive, the library family, and the block version. Cross-check this against the version stamp in the chart's compilation log.

8. Version Compatibility Between D7-SYS Releases

D7-SYS is the Siemens engineering framework that sits on top of SIMATIC STEP 7 and adds the CFC and SFC editors tailored to drive applications. Major releases have introduced support for new drive families and added STEP 7 version compatibility. Verify the exact release notes for your target version at the Siemens Industry Online Support portal before planning a migration.

General compatibility rules of thumb (verify against the D7-SYS release notes for the specific service pack):

• Standard libraries (FBSG*, FBSLIC) can be updated automatically by D7-SYS' Project → Update libraries function. The function reads the chart's required version stamp, locates a compatible pair in the global sdblocks, and re-binds. This works across major D7-SYS versions for standard libraries.
• Custom libraries (KAM, CAM, MAM, OEM) cannot be updated automatically. The mask encodes a CRC of the parameter set that the supplier's tool produced, and the CRC is opaque to D7-SYS. A custom KAM library must be re-exported from the original supplier engineering environment.
• STEP 7 base compatibility depends on the D7-SYS service pack. Newer D7-SYS releases may require a newer STEP 7 SP and will refuse to install on an older STEP 7 base. Refer to the D7-SYS installation manual for the exact STEP 7 compatibility matrix.
• CPU firmware is independent. A D7-SYS V8.x project can be loaded into a CPU 315-2 PN/DP running an older firmware, as long as the S7 program tree is valid. The memory card format (FAT16 with a 16 MB partition for older MMCs, FAT32 for newer 256 MB+ cards) is determined by the CPU, not by D7-SYS.

For projects with standard libraries only, the Update libraries function is the recommended path. For projects with custom libraries, the only reliable path is to install the source D7-SYS version on the maintenance laptop (or in a virtual machine) and load the project ZIP with the original \Global\sdblocks folder intact.

9. Verification Procedure

After a successful compile/download, verify the following checkpoints before declaring the memory card load complete:

If any of the above fails, repeat the placement step and re-verify that the option in Options → Customize → Compile/Download still matches the directory where the files were placed. Switching the option without copying the libraries to the new location will reproduce the missing-library abort.

10. Troubleshooting Matrix

The following matrix maps the most common fault messages to their root cause and remedy. Use it as a fast diagnostic aid in the field.

11. Preventive Measures and Best Practices

1. Always archive the project with the \Global\sdblocks folder in the ZIP. The folder contains all linked library pairs and is mandatory for cross-version load. Use File → Archive → User-defined in SIMATIC Manager and check the S7 libraries option.
2. Document the D7-SYS version and service pack used to create the project. Save this in a PROJECT_INFO.TXT next to the project file, e.g.:

   Project: PressLine42
   Created with: D7-SYS V6.0 SP4 HF7
   STEP 7: V5.4 SP3
   Library sources: MASTERDRIVES VC (FBSGVC.A v2.4.1), KAM001 v1.2.0
   CRC of KAM001.msk: 0xA1B2C3D4

3. Use "System data from project folder" when delivering the project to a third party. This avoids the workstation's global library set and guarantees the shipped libraries are exactly what the chart expects.
4. Keep a clean, versioned library repository for custom KAM/CAM/MAM modules. A Subversion or Git LFS repository with the .a / .msk pairs stored next to the project ZIPs is the most robust approach. Tag each release with the chart's CRC of the parameter set.
5. Avoid automatic library updates on custom modules. The dialog may report success while silently re-binding to a different parameter set. Always keep a backup of the original pair and verify the CRC after an update.
6. If the supplier's .KMZ is suspect, request a new export from the original engineering laptop that produced the project ZIP. The export must use the same D7-SYS service pack. Do not rely on a verbal confirmation of the version — request the manifest.xml from the .KMZ as proof.
7. Use a dedicated MMC card reader rather than the PG slot when possible. Native PG slots occasionally corrupt the FAT16 filesystem on industrial MMCs, especially on MMCs that have been re-inserted many times. The SIMATIC USB card reader (6ES7792-0AA00-0XA0) and the Field PG M4/M5/M6 built-in readers are the only recommended devices.
8. Lock the maintenance laptop's D7-SYS version to the project's required build. Do not auto-update the S7-CFC installation; verify any Windows update does not trigger a STEP 7 SP upgrade that re-allocates library paths.
9. Build a virtual machine template per D7-SYS version. For multi-version support, a VM per major version (V6.0, V6.1, V7.0, V7.1, V8.0, V8.1, V8.2) is faster and more reliable than side-by-side installs on a single Windows instance. Snapshot the VM after install so the maintenance environment can be recreated in minutes.
10. After every successful load, store a checksum of the card image in the project archive. A simple certutil -hashfile S7PROGR.S7P SHA256 is enough to verify that the on-card S7 program matches the offline backup.

12. Flowchart: Compile/Download Recovery Path

The following inline SVG summarises the decision flow an engineer follows when the compile aborts on a missing library. Use it as a quick reference card on the shop floor.

13. Related Siemens Documentation

For the authoritative description of the library loader and the compile/download pipeline, refer to the following Siemens documentation (always cross-check the document revision against the D7-SYS service pack installed on your workstation):

• Siemens Industry Online Support — D7-SYS portal — central entry point for D7-SYS manuals, FAQs, and download links.
• SIMATIC S7-CFC documentation — manual set covering the CFC and SFC editors, the library registry, and the compile/download options.
• SIMATIC S7-300 / S7-400 CPU manuals — MMC handling, MRES procedure, and CPU diagnostic buffer interpretation.
• SINAMICS / MASTERDRIVES parameter manuals — parameter set structure that the KAM masks encode.

14. FAQ