Resolving SSP Sinamics V4.6 Missing Package Error in Scout V4.4

Problem Overview

When opening a SINAMICS S120 project in SCOUT V4.4 on a workstation running STEP 7 V5.5 SP4, the engineering tool reports that an object is bound to a software package that is not installed on the PC. The reported object is the drive-side control unit:

• Object element: SINAMICS S120 CU320-2 PN V4.6
• Object type: Drive control unit (Control Unit, CU320-2 DP/PN)
• Required software package: SSP SINAMICS V4.6 (Sinamics Support Package, V4.6)

The dialog reads MISSING SOFTWARE PACKAGE and the project will not load completely, so offline configuration, online commissioning, and the topology editor all fail until the missing package is supplied to the SCOUT installation. The issue most commonly appears when:

1. A machine builder delivered a project on a different SCOUT/STEP 7 revision than the one installed on site.
2. The PC was re-imaged and SCOUT was reinstalled before the matching SSP files were added.
3. The drive firmware on the CU320-2 (here, V4.6) was upgraded in the field but the engineering tool was never updated to match.

Affected Software Stack

The minimum and recommended software stack to work with a CU320-2 PN carrying firmware V4.6 in a SIMATIC S7-300 / S7-400 environment is:

Reference: Siemens Support - SIMOTION SCOUT V4.4 engineering software and the SIMOTION / SINAMICS compatibility list.

Root Cause Analysis

SCOUT and STEP 7 use a device description registry stored in the Windows registry under the SIEMENS\SINAMICS tree. Each SINAMICS Support Package (SSP) registers the device objects, GSD files, parameter lists, and topology rules for one or more firmware revisions.

When you open a project, SCOUT walks the project tree and resolves each drive object against the registry. If the registry key for SINAMICS S120 CU320-2 PN V4.6 is absent, SCOUT cannot deserialize the object and throws the MISSING SOFTWARE PACKAGE error. The text in the dialog is literal: the project's *.sin container holds a reference to a package GUID that is not present in the local SSP store at %ProgramFiles(x86)%\Siemens\Automation\SCOUT\SSPs.

Common root causes, ranked by field frequency:

1. SSP V4.6 not installed. The most frequent cause. SSPs are not bundled with the SCOUT DVD; they are distributed as separate downloads.
2. Wrong SSP variant installed. A SSP for a different drive family (S110, S210, G120) or a different firmware revision was installed in place of the S120 V4.6 SSP.
3. SCOUT V4.4 Hotfix 4 missing. The Hotfix repairs GSD handling, project migration logic, and several CU320-2 commissioning bugs. Without it, an installed SSP can still fail to load under certain topology conditions.
4. STEP 7 service pack mismatch. SCOUT V4.4 was qualified against STEP 7 V5.5 SP4. Older SP levels occasionally fail the project open handshake.
5. Residual registry keys from a prior SSP. A partial uninstall of an earlier SSP can leave a "ghost" object pointer that conflicts with the new SSP.

Identifying the Required SSP

Before downloading, confirm exactly which SSP you need. The project itself contains the binding information.

1. Open the project on a PC that has the correct SSP installed, or open the project archive (the *.zip or *.sin) with 7-Zip and inspect ...\Project\SINAMICS\S120CU3202PN\4.6\.
2. Read the version tag in device.xml or the OBJECTTYPE header - the value must be CU320-2 PN V4.6.
3. Cross-check the CU320-2 firmware on the physical drive: connect online to one drive from a working PC (or read the diagnostic LEDs and operator panel) and verify firmware V4.6 is loaded. If the field drive is on V4.7 or V4.5, you need that SSP instead.

The drive-side firmware can be confirmed with parameter r0018 (Control Unit firmware version) on the online drive. The expected string for the V4.6 line is 4.6.x.

Solution A: Install SSP SINAMICS V4.6

SSPs for SCOUT are hosted in the Siemens Industry Online Support portal. Two reliable download paths exist:

1. Direct SSP download. Search the Siemens support portal for SSP SINAMICS V4.6 SCOUT V4.4. The result that matches the Software Support Package SINAMICS V4.6 entry is the one to use. Reference: SINAMICS S120 software downloads.
2. Toolbox / DVD archive (Vol2b). The SINAMICS commissioning toolkit (commonly referenced as the "Vol2b" archive) bundles SSPs for multiple firmware revisions. Extract the archive and locate the SSP_SINAMICS_V4.6.exe (or equivalent) inside.

Installation procedure:

1. Close SCOUT and STEP 7 completely. The SSP installer refuses to run if either is open.
2. Right-click the SSP executable and choose Run as administrator.
3. Follow the wizard. Accept the default installation path: %ProgramFiles(x86)%\Siemens\Automation\SCOUT\SSPs\SINAMICS_S120_V4.6.
4. Reboot the PC. SCOUT reads the registry on startup; a restart guarantees the new device list is visible.

Solution B: Apply SCOUT V4.4 Hotfix 4

Even with the correct SSP installed, SCOUT V4.4 has known defects that the Hotfix 4 rollup corrects. The Hotfix is mandatory for stable handling of S120 firmware V4.6 projects and addresses the specific failure mode where the CU320-2 PN object does not register after SSP install.

1. Obtain Hotfix 4 from the Siemens support portal entry linked to SCOUT V4.4 SP1 / Hotfix 4.
2. Stop the SIMATIC services: SIMATIC S7-PCT, SIMOTION IT, and the SIMATIC Device Drivers service if present.
3. Run the Hotfix installer, accept the license, and let it patch the SCOUT installation under %ProgramFiles(x86)%\Siemens\Automation\SCOUT.
4. Restart Windows.

Solution C: Reinstall the Full Software Stack

If the registry is in a corrupt state (for example, ghost SSP keys left by an aborted uninstall), the cleanest path is a stack rebuild. Use this when the project still fails to open after A and B have been applied correctly.

1. Uninstall, in order: SCOUT V4.4, STEP 7 V5.5 SP4, SIMATIC NET (if present), the SSP V4.6 entry, and any residual SIMOTION utilities.
2. Open regedit and delete the key HKEY_LOCAL_MACHINE\SOFTWARE\Siemens\SINAMICS and the Siemens.Automation.Domain* keys under HKEY_CLASSES_ROOT that are no longer referenced.
3. Reboot.
4. Reinstall in this order: STEP 7 V5.5 SP4 → SCOUT V4.4 → SCOUT V4.4 Hotfix 4 → SSP SINAMICS V4.6 → SIMATIC NET (if your project uses routed PROFINET to S7-400).
5. Reboot after each component where the installer prompts.

After the rebuild, re-open the project. SCOUT will now find SINAMICS S120 CU320-2 PN V4.6 in its device list, and the MISSING SOFTWARE PACKAGE dialog will not appear.

Alternative: Re-create the Drive Object

For projects where the drive object is only loosely bound (no specific V4.6-only parameters in use), you can drop the missing device and re-insert it from the SCOUT device catalog at the correct firmware revision. This is appropriate when the original project was created on a newer SCOUT and is being downgraded for service work.

1. Open the project, click OK on the MISSING SOFTWARE PACKAGE dialog (the project loads with the object shown as incomplete).
2. Right-click the SINAMICS object and select Delete.
3. From the SCOUT catalog, drag a fresh SINAMICS S120 CU320-2 PN V4.6 into the project tree.
4. Re-create the axis wizard entries, telegram configuration, and topology for the four S120 drive units. If the previous project was archived, copy these values from the archive's offline parameter dump.

Project Recovery from a *.sin Archive

When the original project file is missing, the SCOUT archive format *.sin retains the package binding GUID. To recover the project without re-creating drive objects manually:

1. Install the correct SSP first (Solution A).
2. In SCOUT, choose Project > Retrieve, point to the *.sin archive, and extract to a fresh directory.
3. Open the retrieved project. With the V4.6 SSP in place, all four S120 drive objects bind to their correct device library.

Verification

After applying the fix, verify the install with the following checks.

Troubleshooting Matrix

Compatibility and Migration Notes

CU320-2 firmware V4.6 is one of the long-lived branches in the SINAMICS S120 line and is still supported as a service release. The key compatibility points are:

• STARTER / SCOUT: V4.4 is the last engineering release line that fully supports CU320-2 firmware V4.6. SCOUT V4.5 (TIA-based) requires a different SSP and does not interop with V4.6 SSPs.
• STEP 7: V5.5 SP4 is the supported SP level; older SPs occasionally fail on project open due to a missing SINAMICS device class patch.
• PROFINET: The CPU315 PN-DP and the CU320-2 PN use Standard Telegram 1, 2, 3, 4, 5, 6, 102, 103, 105, 106, and Siemens-specific telegram 7. The SSP V4.6 enables the full set; downgrading the SSP can hide the higher telegram numbers.
• Drive firmware upgrade path: From V4.6, the supported upgrade targets are V4.7, V4.8, and V5.x (the G130/G150 line). Each target needs its own SSP. There is no in-place firmware upgrade inside the same SSP.

Reference documentation:

• SIMOTION SCOUT V4.4 engineering software manual
• SINAMICS S120 CU320-2 function manual
• SINAMICS S120 List Manual (parameter list) for FW V4.6
• STEP 7 V5.5 SP4 release notes

Best Practices for Field Service

To avoid hitting the MISSING SOFTWARE PACKAGE dialog during a service visit, maintain a known-good engineering image.

1. Keep a dedicated image or VM with STEP 7 V5.5 SP4 + SCOUT V4.4 HF4 + SSP V4.6 (and any other SSPs your plant uses) pre-installed.
2. Document the project stack: for every project, note the STEP 7 SP, SCOUT version, Hotfix level, and SSP version. Store the readme inside the project Documents folder.
3. When a machine is delivered, capture the engineering PC image using a sector-based tool (for example Acronis True Image) and store the backup alongside the project archive.
4. When commissioning, run Upload to PG on every drive before the first power-up. Save the resulting parameter file in the project folder. This gives you a known-good V4.6 parameter set if the project has to be re-created.

FAQ