Fix: Distributed Safety V1 Library Missing in STEP 7 V5.5

Problem Description

After installing SIMATIC Distributed Safety V5.4 SP5 on a workstation that already runs STEP 7 V5.5 SP2 (Windows 7 Professional 32-bit), the Distributed Safety (V1) library does not appear in the SIMATIC Manager project tree, in the File → Open → Libraries tab, or in the standard library browser. The user has confirmed that Distributed Safety was installed without any visible error and that both STEP 7 and Distributed Safety have been re-installed with no change in behavior. The Safety programming language editor (F-FUP / F-KOP / F-AWL) and the option package entry under Start → SIMATIC → STEP 7 → Distributed Safety are present, yet the library container is empty or absent.

Root Cause Analysis

SIMATIC Manager stores all standard and option-supplied libraries under a single, version-dependent directory and registers them through a hidden master project list. When the Distributed Safety installer finishes, it must both copy the .s7l container into S7LIBS and add an entry to the user/library list. If the second step fails, the user can still locate the file on disk and open it explicitly. The most frequently observed root causes are:

1. Library registration was not performed by the Distributed Safety setup. The container file Distributed Safety (V1).s7l exists on disk but is not in the SIMATIC Manager library catalog.
2. The library is hidden through SIMATIC Manager → File → Manage. This dialog allows the user to suppress specific libraries and projects from the open dialog, so a previously hidden library appears to be missing.
3. Installation order did not satisfy the option-package requirements: STEP 7 must be installed before Distributed Safety, and the two must be at compatible service-pack levels. DS V5.4 SP5 expects STEP 7 V5.4 SPx or V5.5 SPx.
4. Windows user rights / UAC prevented the installer from writing to Program Files\Siemens\Step7\S7LIBS. On Windows 7 the installer must be launched with administrator rights even when the user account is in the local Administrators group.
5. Corrupted S7LIBS index after an upgrade or restore from backup, leading to an empty library list even though the original .s7l files are intact.

Standard Library Location and File Layout

The Distributed Safety V1 library is a standard offline library (file-based) that ships with the option package. SIMATIC Manager opens it as a read-only source for F-blocks such as F-FB, F-DB, and the standard safety function blocks used in F-shield programming.

Solution 1 — Browse Manually to the Library File

The fastest recovery is to open the library by explicit path, which proves that the container is installed and accessible to SIMATIC Manager. Once opened, the F-blocks can be copied into the user project as a workaround for the missing catalog entry.

1. Launch SIMATIC Manager.
2. Select File → Open.
3. In the Open dialog, switch the tab to "Libraries".
4. Use the toolbar "Browse" button and navigate to: C:\Program Files\Siemens\Step7\S7LIBS\
5. Select the file Distributed Safety (V1).s7l (or the localized equivalent).
6. Confirm with Open. The Distributed Safety F-block tree now appears in the right pane.

If the file is found and opens, the library is installed correctly — only the catalog registration is missing. Continue with Solution 3 to re-register it for future sessions.

Solution 2 — Unhide the Library via File → Manage

SIMATIC Manager exposes a list-management dialog that can hide libraries from the Open dialog. This is the most common cause of the symptom when a colleague or a previous installation session has marked the library as hidden.

1. In SIMATIC Manager, choose File → Manage.
2. The Manage dialog opens with two columns: visible projects / libraries and hidden ones.
3. Locate Distributed Safety (V1) in the hidden list.
4. Select the entry and click Display to move it back to the visible column.
5. Confirm with OK and re-open the File → Open → Libraries tab to confirm the library is listed.

Solution 3 — Re-register the Library Catalog

When Solution 1 works (file exists) but the catalog does not list it, the S7LIBS master index needs to be rebuilt.

1. Close SIMATIC Manager completely.
2. Open Windows Explorer and navigate to C:\Program Files\Siemens\Step7\S7LIBS\.
3. Verify that Distributed Safety (V1).s7l is present. If absent, re-install the option package.
4. Delete the file S7LIBR.DIR from the same directory if it exists (it is a transient index cache that SIMATIC Manager recreates on next start).
5. Re-launch SIMATIC Manager. The next time you select File → Open → Libraries, the indexer reads the directory contents and the Distributed Safety entry is restored.

Solution 4 — Verify F-Block Open Capability

Library registration is a UI feature; the underlying ability to open F-blocks depends on the option package being properly registered with the F-programming tools. The integrity check is:

1. Create a temporary S7 program on a CPU that supports F-functions (e.g., CPU 317F-2 PN/DP).
2. Insert an F-FB or F-DB in the safety program.
3. Double-click the F-block. If the F-AWL / F-FUP / F-KOP editor opens, the option package is functional and the issue is purely catalog-level.
4. If the editor does not open, the Distributed Safety installation is incomplete — re-run the setup, this time with the target installation path set to the same drive as STEP 7 and with administrator rights.

Solution 5 — Re-install in the Correct Order

Installations performed out of sequence leave the option package unable to integrate with STEP 7. The supported sequence on a 32-bit Windows 7 host is:

1. Install STEP 7 V5.5 (English or German) with administrator rights.
2. Apply STEP 7 SP2 and any required hotfixes.
3. Install Distributed Safety V5.4 SP5. The setup detects the STEP 7 installation and writes the library into the correct S7LIBS folder.
4. Install S7-PLCSIM V5.4 SP5 (optional, for F-offline simulation) and S7 F-ConfigurationPack matching the F-CPU hardware used.
5. Reboot. Launch SIMATIC Manager and check the library list before opening any project.

Solution 6 — Workaround: Copy F-Blocks from an Existing Program

If a parallel workstation has the library open and the local installation cannot be repaired in time, F-blocks can be exported as a source file and re-imported:

1. On the working PC, in the Distributed Safety library, right-click an F-block and choose Generate Source File with STL or F-AWL source format.
2. Copy the generated .awl / .fup file to the affected PC.
3. In SIMATIC Manager on the affected PC, open the target F-program and choose Options → Insert → Source File (or drag the source onto the Sources folder).
4. Compile the source. The F-block is inserted into the program and is fully usable for the F-CPU target.

Compatibility Matrix — STEP 7 / Distributed Safety / F-CPU

Verification — Confirm the Library is Operational

1. Open SIMATIC Manager and choose File → Open → Libraries. Distributed Safety (V1) appears in the list without browsing.
2. Open the library and expand Blocks. The catalog should contain at minimum:
   • F-FB GEN_DP / F-FB GEN_F (failsafe blocks for PROFIsafe and F-I/O)
   • F-DB templates for F-runtime groups
   • F-Shield blocks for safety-related program sections
3. Create a new F-runtime group in any S7 program; the F-program editor accepts the library blocks without raising "Block not found" or "F-CPU does not support block" errors.
4. Run a consistency check: Options → Safety Program → Check Consistency. The result is "No errors" for an empty runtime group.
5. Open a previously working F-block in the F-FUP / F-KOP editor. The block is opened, compiled, and downloaded to the F-CPU via Target System → Download without raising dialog "Distributed Safety not installed".

Troubleshooting Matrix

FAQ