Connecting SIMOTION D425 6AU1425-0AA00-0AA0 via Scout Software

1. Problem Context: The SIMOTION D425 Connectivity Gap

The SIMOTION D425 with order number 6AU1425-0AA00-0AA0 is a first-generation SIMOTION controller with an integrated SINAMICS S120 drive line. Engineers frequently reach for SCOUT TIA when they first unpack a programming device (PG) that already has TIA Portal V13 through V18 installed. The result is predictable and frustrating: SCOUT TIA only lists the newer 6AU1425-2AA... variant (D425-2 DP/PN) in its hardware catalog, and the older D425 control unit cannot be created, opened, or diagnosed.

This article documents the supported software path for the legacy D425, including the exact Scout variant, the matching STEP 7 baseline, the integrated webserver fallback, and the diagnostic buffer procedure.

2. Device Identification: D425 vs D425-2

Siemens released the SIMOTION D4xx family in two major hardware generations. The article-number suffix determines the engineering tool path. Misidentifying the variant is the most common cause of the "device not in catalog" symptom.

Read the device label on the front plate of the D425 module. The order number is printed on the right-hand side under the Siemens logo. If the second field of the MLFB reads -0AA00- it is the legacy D425. A -2AA00- or -2AD00- indicates the D425-2 family and SCOUT TIA can be used directly.

3. Why SCOUT TIA Cannot See the Legacy D425

The SIMOTION option package for TIA Portal only ships object lists, GSD-equivalents, and device descriptions for hardware released or still serviced at the time of the SCOUT TIA build. The legacy D425 is excluded because:

1. No new firmware is being produced, so no new TIA option package is generated for it.
2. The hardware catalog inside SCOUT TIA is generated from the same device pool as TIA Portal's hardware catalog; without a registered MLFB, the device cannot be inserted into a TIA project.
3. TIA Portal V15, V15.1, V16, V17, and V18 all carry the same exclusion: only 6AU1425-2AA... appears, even with the latest HSP (Hardware Support Package) installed.

The mismatch is not a license issue, an HSP problem, or a corrupt install. The legacy D425 is simply outside the supported set of the TIA toolchain. Use the SIMATIC Manager / SCOUT Standalone path instead.

4. Required Software Stack

Two supported paths exist for diagnosing the legacy D425. Both are based on the same SCOUT engine, only the host shell differs.

4.1 SCOUT Standalone (Recommended for diagnostics-only work)

• SCOUT V4.4 SP1 (or later standalone build) with HF (hotfix) installed for the D425 hardware family.
• Does not require STEP 7 V5.x installation; it is a self-contained engineering shell.
• Includes the device catalog, the SINAMICS drive configurator, and the integrated webserver launch point.
• Can be installed on Windows 7 SP1 / Windows 10 (LTSC) 64-bit; check the current readme for the exact supported Windows build.

4.2 SCOUT for STEP 7 V5.x

• STEP 7 V5.5 SPx (SP4 or later) is mandatory as the host shell.
• SCOUT V4.4 (or V4.4 SPx) installed as an add-on inside SIMATIC Manager.
• Required when you also need to manage the project on a STEP 7 V5.x S7 program side-by-side with SIMOTION programs.
• The combo is the only way to retain compatibility with V13-style projects that the user may have on the PG.

5. Scout Version Compatibility Matrix

Match the SCOUT version to the runtime firmware currently flashed on the D425. A newer SCOUT will refuse to go online against an older firmware, and a much older SCOUT cannot read newer diagnostic data structures.

6. Webserver Fallback (No SCOUT Installed)

The SIMOTION D425 has an integrated webserver that exposes a substantial subset of the diagnostic buffer, the alarm history, and the SINAMICS drive state. It is the fastest way to confirm a controller is alive and to read recent alarms when installing SCOUT is not possible.

1. Connect the PG Ethernet port directly to the D425 X120 (PROFINET port 1) or X130 (port 2) service interface.
2. Configure the PG IP to 169.254.11.22 with mask 255.255.0.0 (the default service IP of the D425 is 169.254.11.21 for X120 or use the configured address from the project).
3. Open a browser and navigate to https://169.254.11.21 (or the configured address). Accept the self-signed certificate warning.
4. Log in with the configured user rights; the default administrator account is simotion with the password set during commissioning (or SIMOTION on a brand-new unit).
5. Navigate to Diagnostics → Diagnostic Buffer and Diagnostics → SINAMICS State to read faults and warnings.

The webserver is read-only for project changes but covers > 80% of the data a service engineer needs for a first triage. Use it whenever a customer will not allow a full Scout install, or when a foreign PG is on hand.

7. STEP 7 V5.x + SCOUT Installation Procedure

For the most complete engineering access (online, project edit, firmware update, trace, drive control panel), follow this exact sequence:

1. Verify OS compatibility. Windows 7 SP1 (64-bit), Windows 10 LTSC 2019, or Windows Server 2016 are commonly accepted. Disable UAC during installation to prevent registry-write failures.
2. Install STEP 7 V5.5 SPx from the original DVD or Siemens Automation License Manager image. Reboot.
3. Install SCOUT V4.4 (or whichever build matches the on-board firmware). Select the Add-On installation; SCOUT registers itself into the SIMATIC Manager shell.
4. Install SIMOTION firmware support package if your SCOUT DVD has a separate SIMOTION SCOUT — Support Package folder. This package adds the D425 catalog entries.
5. Apply hotfixes (HF) released against your SCOUT build. Hotfixes fix specific diagnostic buffer parsing bugs and are required for V4.3 firmware to read all entries.
6. Transfer the Automation License for SCOUT (and a separate one for SINAMICS commissioning) from the USB license key to the local hard disk using the Automation License Manager.
7. Restart the PG and launch SIMATIC Manager. SCOUT is now visible in the Tools → SIMOTION Scout menu.

8. Online Connection and Diagnostic Buffer Read

1. Create a new SIMOTION project in SCOUT and add the D425 (6AU1425-0AA00-0AA0) from the catalog.
2. Configure the PROFINET interface (X120/X130) to match the unit's IP address. Default is 169.254.11.21; change in Project → Properties → Address if the unit has a different fixed address.
3. Right-click the D425 in the project tree and select Connect to target system. Confirm the IP and subnet.
4. Once online, open Target system → Diagnostics → Diagnostic buffer. The buffer lists the most recent 200+ events with timestamp, event class, and associated SINAMICS fault code.
5. For drive-side faults, open Drive → Diagnostics → Faults / Warnings. Each entry shows the SINAMICS fault number (F-code), the component, and the diagnostic text.
6. Use Trace to record the analog and digital channels leading up to a fault. The D425 supports up to 4 trace sessions concurrently.

The diagnostic buffer is non-volatile and survives power cycles. It is the first stop for any field service call. Always export the buffer (Export to CSV) before clearing faults, because clearing zeroes the buffer and destroys forensic data.

9. Firmware Update Procedure (V4.3 Final)

1. Confirm the unit is at V4.2 or earlier; V4.3 is the target.
2. Open the project, connect online, and read the current firmware version from Target system → Device version.
3. Right-click the D425 and select Target system → Firmware update. Browse to the unzipped firmware directory that contains the SIMOTION_D4xx_V4_3.upd file (and matching SINAMICS CU firmware).
4. Select the components to flash: SIMOTION runtime, SINAMICS control unit, and (optionally) the drive's CF card image.
5. Click Start update. The D425 reboots automatically twice; do not power-cycle the unit during the update window.
6. After reboot, reconnect and verify the new firmware version in the Device version dialog. Perform a RAM-to-ROM save to persist the upgrade.

10. Verification Checklist

Run through this matrix to confirm a healthy online session before returning the unit to production:

11. Troubleshooting Matrix

12. Field-Proven Caveats

• The D425 cannot be migrated to the D425-2 hardware without a full re-commission. There is no field conversion kit.
• Spare CF cards must be Siemens-branded (6AU1400-xAAxx-xAA0 family). Industrial-grade cards from third parties frequently fail to boot the SIMOTION runtime.
• When replacing a defective D425, the new unit's MAC address differs from the old one. Update the PROFINET device name and IP before going online, otherwise the IO controller will not see the replacement.
• The D425 stores the project on the CF card, not in the unit's flash. Always keep a project backup on the engineering PG; a corrupted CF card is the most common cause of "unit will not boot."
• Newer Windows 10 builds (1909 and later) can break the SINAMICS commissioning tool's COM server. Pin the OS to 1809 LTSC for production PGs that service SIMOTION fleets.

13. Frequently Asked Questions