Resolving SIWAREX CS SICS_DR FB42 Password Compile Error in TIA Portal
The SIWAREX CS weighing module (Siemens order number 7MH4910-0AA01) integrates a high-precision electronic weighing system into the SIMATIC ET 200S distributed I/O family. Engineers commissioning multi-scale systems frequently encounter a compiler error from the SICS_DR (FB42) function block when the project is built in TIA Portal. The diagnostic message — "The block can only be compiled with a valid password." — blocks generation of the user program and prevents download to the IM 151-8 PN/DP interface module. This reference documents the root cause, the official resolution path, and the verification procedure for projects that contain up to six SIWAREX CS modules on a single station.
1. Problem Description
When a TIA Portal project that references the SICS_DR function block (FB42) is compiled, the compiler halts and emits the following diagnostic in the information pane:
SICS_DR (FB42): "The block can only be compiled with a valid password."
Affected configurations observed in the field:
- CPU: IM 151-8 PN/DP (6ES7151-8AB01-0AB0 or comparable firmware variants) used as PROFINET IO controller with up to 6 SIWAREX CS modules on ET 200S stations.
- Software: TIA Portal V11 SP2, V12 SP1, V13 SP1, and V13 SP2 (the symptom is version-independent — see Section 4).
- Library source: the FB was imported by drag-and-drop from a copied project archive rather than from the official SIWAREX installation package.
- Block count: any number of instances, but typically 1–6 SIWAREX CS channels per IM 151-8 station.
The error is not caused by missing hardware, missing GSD files, or a defective SIWAREX module. It is a software-side protection mechanism inside the SICS_DR source.
2. Root Cause Analysis
SICS_DR is a Siemens-supplied, know-how protected (KHP) function block. The source STL is shipped in a compiled-with-password state to protect proprietary scale-handling logic, calibration routines, and SIWATOOL command routing. The block cannot be re-compiled, re-linked, or have its interface regenerated unless the original Siemens SIWAREX CS library is installed and the protection password is present in the active TIA Portal project environment.
Three scenarios trigger the error message:
| Scenario | Mechanism | Detection |
|---|---|---|
| 1. Block copied from another project | Know-how protection travels with the block; the password from the source project does not transfer to the destination environment. | Compiler reports SICS_DR FB42 KHP error on every build. |
| 2. SIWAREX library installed but version mismatch | Older library (e.g., V1.x) referenced against a TIA Portal V13 project, or vice versa. Interface signatures diverge; re-compile is forced and fails. | Version warning in the "Libraries" pane; cross-version interface symbols. |
| 3. Library not installed at all | FB exists as a stand-alone object; password is not present in the program source. | Right-click on FB42 → "Object Properties" → "Protection" tab is missing or empty. |
The block is intentionally non-editable. The intended workflow is for the integrator to call the block as a black box, not to re-compile it. However, TIA Portal still re-compiles all blocks in the program during a full project build, which is why the password must be available even if the integrator never opens the FB editor.
3. SIWAREX CS Hardware and Interface Overview
Before resolving the compile error, verify that the engineering environment matches the SIWAREX CS hardware revision. The base module is the 7MH4910-0AA01; the firmware/function variant is selected with the rotary switch on the front of the module (positions 0–3 for weighing modes, 9 for SIWATOOL).
| Parameter | Value |
|---|---|
| Siemens order number | 7MH4910-0AA01 |
| Module width | 15 mm (ET 200S single slot) |
| Resolution | 16-bit (65 535 divisions) / 0.5 µV per division |
| Accuracy class | III (up to 3 000 d, configurable) |
| Load cell excitation | 4.85 V DC ± 2% |
| Measuring rate | 10 Hz, 20 Hz, 50 Hz, 100 Hz (selectable) |
| Communication | Backplane bus (PROFIBUS / PROFINET via IM 151) |
| Configuration software | SIWATOOL CS (V4.x and later) |
| Function blocks for S7 | SICS_BA (FB40), SICS_DR (FB42), SICS_SC (FB41) |
| Cycle time (typical) | 100 ms at 10 Hz / 10 ms at 100 Hz |
Source: SIWAREX CS Quick Guide V4.0 and SIWAREX CS Equipment Manual.
4. TIA Portal Library and Version Compatibility Matrix
The official SIWAREX CS library is delivered as a TIA Portal global library ("SIWAREX_CS_TIA") and must be installed into the TIA Portal library catalog. Use the matrix below to align library version with the TIA Portal version used in the project.
| TIA Portal Version | SIWAREX CS Library | SICS_DR FB Number | Notes |
|---|---|---|---|
| V11 SP2 / V12 SP1 | SIWAREX_CS V1.0.x | FB42 (V1.0) | STEP 7 V11 generated; may require upgrade tool to V13. |
| V13 SP1 | SIWAREX_CS V1.1.x | FB42 (V1.1) | First release with native TIA V13 KHP integration. |
| V13 SP2 | SIWAREX_CS V1.2.x | FB42 (V1.2) | Adds DR command-set extensions for legal-for-trade use. |
| V14 SP1 / V15.1 | SIWAREX_CS V2.0.x | FB42 (V2.0) | Supports S7-1500 ET 200MP / ET 200SP migration paths. |
| V16 / V17 | SIWAREX_CS V2.1.x | FB42 (V2.1) | Final release for classic ET 200S SIWAREX CS line. |
When the library version is older or newer than the TIA Portal version, the compiler treats the FB interface as modified and tries to recompile, which trips the KHP check. Pin both to the same major version.
5. Solution Procedure
Follow the steps below in the order given. The procedure applies to TIA Portal V11 through V17 for the IM 151-8 PN/DP with one to six SIWAREX CS modules.
5.1 Prerequisites
- Administrator rights on the engineering workstation.
- Siemens automation license or active support contract to access the SIWAREX CS library download area on Siemens Industry Online Support.
- The correct library version matching the TIA Portal version (see Section 4 matrix).
- A working backup of the current TIA project (.ap11 / .ap12 / .ap13 / .ap14 / .ap15 / .ap16 / .ap17 archive).
5.2 Step-by-Step
Step 1 — Open a TIA Portal administrative command prompt. The library install requires write access to %ProgramData%\Siemens\Automation\Portal Vxx\Library.
Step 2 — Remove the unauthorized SICS_DR copy. In the project tree, navigate to Program blocks → System blocks (or Master copies) and delete every SICS_DR (FB42) and SICS_BA (FB40) instance that was pasted in from another project. Also delete any user-defined data types (UDTs) named SICS_CMD, SICS_PRM, or SICS_DAT that came from the foreign project — they are version-tagged.
Step 3 — Install the official SIWAREX CS library. Run the supplied executable (e.g., SIWAREX_CS_TIA_Vx_x.exe) or open the global library archive (.zal) directly in TIA Portal from Options → Global libraries → Open library. Confirm that the library appears in the Libraries pane under Global libraries → SIWAREX_CS.
Step 4 — Drag the SICS_DR master copy into the project. In the Libraries pane, expand SIWAREX_CS → Master copies → Weighing and drag the SICS_DR (FB42) master copy into Program blocks. Repeat for SICS_BA (FB40). The password travels with the library copy; this is the only mechanism that loads the KHP password into the project.
Step 5 — Verify the protection state. Right-click SICS_DR (FB42) → Object properties → Protection. The status must read "Know-how protected (password-protected)" with the author "Siemens AG" or "SIWAREX". If the field is empty, the master copy was not picked up — repeat Step 4.
Step 6 — Re-instantiate the FB calls in OB1 (or cyclic OB). The original call sites remain intact, but the FB signature must match the new version. Re-compile the project. The error message should no longer appear.
Step 7 — Perform a full project build. Use Project → Compile → Software (rebuild all blocks). Check the information pane for residual warnings. A clean build shows no SICS_DR KHP entry.
Step 8 — Download to IM 151-8 PN/DP. Connect via PROFINET, select the IM 151-8, and download the program. The IM 151-8 does not store the program locally — it is downloaded to the higher-level S7 CPU. For ET 200S standalone configurations, ensure an S7-300/S7-1200 CPU is in the same station.
6. Verification Checklist
After the fix, validate the system end-to-end:
- Compile cleanliness. Zero entries referencing SICS_DR in the Compile information pane.
- Online block consistency. Right-click the S7 CPU → Compare online/offline. SICS_DR and SICS_BA must show "Identical".
- Diagnostics buffer. Connect online, open Online & diagnostics → Diagnostics buffer. No "Parameter assignment error" (OB 82) entries for the SIWAREX CS slots.
- SIWATOOL command echo. Open SIWATOOL CS V4.x, connect via RS-232 (6ES7 132-4BB31-0AA0 terminal module), and read the parameter set. Confirm the configured measuring rate, gross weight zero, and filter settings are accepted by the module.
- Multi-channel test. With six modules installed, place a known test weight on each scale and verify the assigned process image addresses (default I/O range: 8 bytes input, 4 bytes output per SIWAREX CS). Drift should remain within ± 1 division over 5 minutes at constant temperature.
- Synchronous error handling. If a parameter assignment error appears after download, the SIWAREX CS rejects the data record and issues a synchronous error — see SIWAREX CS Equipment Manual, Section 7 — Messages.
7. Field-Proven Workarounds
If the official library cannot be obtained (locked engineering workstation, expired support contract), the following temporary workarounds unblock commissioning but must be replaced with the official solution before site acceptance:
-
Hotline route. Siemens operates a dedicated SIWAREX hotline at
[email protected]. Provide the project archive plus a screenshot of the error. The hotline returns an unlocked copy of the FB for the specific TIA Portal version. - Pin-compatible PLC swap. The SICS_DR FB is functionally identical for ET 200S and ET 200SP variants. If the project also contains an ET 200SP station with a SIWAREX WP231 (7MH4960-6AA01), the block can be retargeted with a one-time library re-import.
- Do not edit the FB. Never attempt to remove the KHP attribute via hex editing or third-party STL utilities. Doing so corrupts the block checksum and causes an SF fault on the CPU on the next cold start.
8. Common Error Variants and What They Mean
| Compiler Message | Real Cause | Resolution |
|---|---|---|
| "The block can only be compiled with a valid password." | SICS_DR KHP password not in project | Install official library and drag master copy (Section 5). |
| "Interface of the block SICS_DR has changed." | Version mismatch between block copy and library | Replace with master copy from matching library version. |
| "The data type SICS_CMD is not defined." | UDT set was deleted in Step 2 | Drag the UDTs from the library Types folder into the project. |
| OB 82 "Parameter assignment error" for SIWAREX CS | Module rejects DR data record | Check DR command 01–0F order; reference manual Section 7. |
| "Instance DB cannot be generated for SICS_DR" | FB42 still showing as multi-instance candidate | Set the FB as a single-instance block (Object properties → Attributes). |
9. Migration Notes for S7-1200 / S7-1500 Hosts
When the project is later migrated to a S7-1200 (with SM 1278 SIWAREX extension) or S7-1500 (with TM SIWAREX WP231), the original SICS_DR block is replaced by the SIWA library blocks (FW_x, FxScale, etc.). The know-how protection mechanism is preserved across the migration; the same root cause can re-appear if the new SIWA library is not installed before compilation. The migration must be performed with TIA Portal V14 SP1 or later, and the IM 151-8 PN/DP must remain in the configuration until the cutover is complete.
10. Frequently Asked Questions
What does the SICS_DR FB42 KHP compile error mean in TIA Portal?
It means the SICS_DR function block is in your project without its original Siemens know-how-protection password. The block was likely copied from another project instead of imported from the official SIWAREX CS global library. Install the matching SIWAREX_CS library and re-drag the SICS_DR master copy into Program blocks so the password is restored.
Which TIA Portal versions are affected by the SICS_DR password error?
The error has been reported on TIA Portal V11 SP2, V12, V13 SP1, and V13 SP2. It is not a version defect — it is a built-in protection mechanism that triggers on any TIA Portal version when the official library is missing or mismatched.
Can the SICS_DR FB be used on SIMOTION controllers?
No. Siemens officially states that FB SICS_BA and FB SICS_DR are not available for SIMOTION. Use an S7-300, S7-1200, S7-1500, or an IM 151-8 PN/DP interface module with an S7 CPU in the same station. See Siemens Support entry 21554724 for the full statement.
How many SIWAREX CS modules can run from a single IM 151-8 PN/DP?
Up to 12 SIWAREX CS modules can be plugged into a single ET 200S station, limited by the backplane bus address space and the configured I/O area of the S7 CPU. Field-proven configurations commonly use six modules for parallel bin scales, with each module consuming 8 bytes of input and 4 bytes of output process image.
Where can I obtain the official SIWAREX CS library for TIA Portal?
Download the matching library version from Siemens Industry Online Support at support.industry.siemens.com by searching for "SIWAREX CS TIA Portal library". For legacy or locked-down projects, contact the SIWAREX hotline at [email protected] with your project archive.
Why does the error appear even though I never open the SICS_DR FB editor?
TIA Portal performs a full project compile on every build, which forces re-compilation of all referenced blocks — even know-how-protected ones that the user has not modified. The password must be present in the active TIA project environment, not in a separate archive, for the re-compile to succeed.