Resolving SIMOTION D410-2 Error 20005 After Power Loss

Problem Summary

The SIMOTION D410-2 DP/PN is a compact, distributed motion controller from Siemens that integrates a SIMOTION D410 CPU module with the SINAMICS S120 drive platform. The device combines motion control, technology functions, and drive control in a single, space-saving form factor commonly deployed in packaging, printing, woodworking, converting, and textile machinery where a stand-alone controller is mounted close to the motor.

One of the more confusing fault scenarios occurs when a machine that has been powered down for an extended period (days to weeks) is re-energized. The controller fails to reach RUN mode, the RDY LED flashes red, and the diagnostic buffer shows error 20005 with bit 0 set, encoder number 0, reason code 0x1H. The Run/Stop LED remains yellow (STOP), the encoder supply LED (OUT-5V) shows green, and SF/BF remains OFF. The user has tried swapping the motor and the fault persists, which rules out a simple motor-side fault and points instead at controller configuration, encoder parameterization, or project corruption.

This article maps the LED states to controller condition, interprets error 20005 in the context of a cold-start from a long power-down, and walks through the diagnostic and recovery procedure using SIMOTION SCOUT (or TIA Portal with SIMOTION) and the SINAMICS STARTER / SCOUT integrated view. The official Siemens support entry 99006251 consolidates the LED and diagnostic descriptions used here, and the SIMOTION D410-2 Commissioning and Hardware Installation Manual is the authoritative commissioning reference.

SIMOTION D410-2 LED Status Reference

The D410-2 front panel provides four primary status LEDs on the controller module and additional LEDs on the integrated SINAMICS portion. Correct interpretation of the LED combination is the first diagnostic step before opening any software tool. The exact mechanical layout and the order of the LEDs are documented in the D410-2 Commissioning Manual.

The combination RDY red flashing + RUN/STOP yellow + OUT-5V green + SF/BF OFF indicates that the firmware has booted successfully, the encoder supply rail is intact, and the fieldbus is not in fault, but a Technology Object (typically an axis, encoder, or output cam) is unable to start. This is consistent with a SINAMICS Integrated parameterization or commissioning fault rather than a wiring or fieldbus problem.

SINAMICS Integrated State LEDs

The SINAMICS Integrated portion of the D410-2 has its own status LED (typically labelled RDY on the integrated module). When the integrated drive is in fault, the SINAMICS RDY LED shows red and the firmware exposes the message "SINAMICS Integrated in fault state (Check parameterization/configuration)" in the SIMOTION device diagnostics. This message is the entry point for the recovery procedure described below and is documented in Siemens support entry 99006251.

Fault Code 20005: Encoder / Technology Object Error

Error code 20005 in SIMOTION is the generic Technology Object alarm. The numerical ID identifies the alarm class; the sub-fields (bit number, encoder number, reason code) determine the exact fault. The exact meaning of each reason code is documented in the SIMOTION Motion Control Technology Objects function manual and in the SCOUT / TIA Portal information system for the specific TO type. Always cross-check the reason code against the documentation that ships with the firmware version loaded on your controller.

Why a 20-Day Power-Down Changes the Behavior

SIMOTION D410-2 retains its persistent project data and most drive parameters in non-volatile memory (CompactFlash on older units, MMC/SD card on newer units, plus internal NVRAM for the real-time clock). However, the following time-dependent elements can degrade or require re-initialization after a long power-down:

• Backup capacitor for the internal clock / diagnostic buffer: if discharged, the time stamps of the diagnostic entries will reset to default and the controller may flag an RTC warning or a configuration-check required warning on first boot.
• Encoder absolute-position buffers: if the encoder is an absolute encoder (EnDat, SSI, PROFIBUS / PROFINET encoder) and the drive has lost the multi-turn counter reference, the SINAMICS may report F3xxx faults and the SIMOTION TO may surface the alarm as 20005.
• SINAMICS parameter consistency check on first start: the SINAMICS Integrated performs a CRC check on the drive parameter set on every boot. If the parameter set in the device differs from the project loaded into the controller, the SINAMICS enters fault and SIMOTION surfaces a TO alarm.
• DRIVE-CLiQ topology validation: the firmware re-scans the DRIVE-CLiQ topology; any component that has changed serial number or has not been re-commissioned will be flagged.
• Know-how protection / password retry counter: some firmware versions reset the password retry counter on long power-down and may trigger an additional alarm on the first boot.

If the machine was working before the power-down, the most likely root cause is one of the first three items above rather than a hardware failure of the encoder or motor. The source confirms the motor was swapped with the same result, which is strong evidence that the fault is not on the mechanical or motor side.

Connecting to SINAMICS Integrated via SCOUT / STARTER

SIMOTION D410-2 has two distinct online interfaces available from a service PC:

1. SIMOTION SCOUT (classic) or TIA Portal with SIMOTION option: connects to the SIMOTION controller, exposes the project, the Technology Objects, and the diagnostic buffer.
2. SINAMICS STARTER (or Startdrive / SCOUT integrated SINAMICS view): connects to the SINAMICS Integrated portion of the D410-2, exposes drive parameters, the alarm history, and the parameter view.

The diagnostic question in the source case ("if I want to change the SINAMICS that is integrated in SIMOTION 410-2, can I do this?") resolves as follows:

• Yes, the SINAMICS Integrated is accessible as a sub-device. From SCOUT, expand the SIMOTION D410-2 node, then expand the SINAMICS Integrated sub-node. Right-click and select "Online > Connect to target system". From STARTER, use "Accessible nodes" over PROFINET or PROFIBUS, and select the SINAMICS node whose IP / PROFIBUS address matches the integrated drive.
• If the project on the controller is password-protected and you do not have the password, you can still connect online and read the parameter set, but you cannot upload the parameter set to your PC as a project file without the appropriate access level. The OEM must provide the project archive.

Step-by-Step Diagnostic and Recovery Procedure

The following procedure assumes the LED combination described above is present after re-energizing the machine. The procedure is ordered from the least invasive check (read the diagnostic buffer) to the most invasive (re-commission the drive).

1. Establish online connection to the SIMOTION controller.
   • Set the service PC Ethernet interface to the same subnet as the D410-2 (factory default IP address of the D410-2 PROFINET interface is 192.168.0.1; verify on the device label).
   • Open SCOUT, choose Project > Accessible nodes, and select the SIMOTION D410-2 node.
   • If you do not have a project on the PC, choose "Go online" (without opening a project). The SIMOTION device view will open directly.
2. Read the diagnostic buffer.
   • Open the SIMOTION device diagnostics (double-click the device, then the "Diagnostics" tab).
   • Note all entries. Sort by time stamp; the earliest entry after the power-up is the root cause alarm.
   • Open the entry for alarm 20005 and capture the full alarm text, the TO name, and the reason code in HEX.
3. Cross-check the SINAMICS Integrated alarm buffer.
   • From SCOUT, open the SINAMICS Integrated node and connect online.
   • Navigate to Diagnostics > Alarm history.
   • Record all Fxxxx (fault) and Axxxx (alarm) codes. Common codes after long power-down are F3xxx (encoder), F5xxx (configuration), F7xxx (communication), and F8xxx (DRIVE-CLiQ topology).
4. Acknowledge faults and attempt a controlled ramp-up.
   • In SCOUT, use the toolbar "Acknowledge" button or the command _acknowledge_faults in the ST script editor.
   • In STARTER, click the "Acknowledge faults" button on the operator panel.
   • Set the controller to RUN from SCOUT (CPU > Operating mode > RUN, or the toolbar button). Observe the LED transition.
5. If the fault returns, capture and address each SINAMICS F-code individually.
   • For F3xxx encoder faults, check the encoder cable continuity, the connector pinout (especially the 5 V supply), and the DRIVE-CLiQ connection.
   • For F5xxx configuration faults, compare the device parameter set against the project; restore from project using "Load to target device".
   • For F7xxx communication faults, verify PROFINET device name and IP, check the topology editor in SCOUT.
6. If you have the OEM project archive:
   • In SCOUT, open the project archive (File > Retrieve > Project archive).
   • Go online to the D410-2, then choose "Load to target device" (CPU and SINAMICS Integrated). The load operation will overwrite the device parameters with the project values.
   • After the load completes, power-cycle the D410-2 (de-energize, wait 30 s, re-energize) to force a clean boot.
7. If you do not have the OEM project:
   • Contact the machine builder / system integrator to obtain the project archive and the password if the project is protected.
   • As a temporary workaround, the controller can be operated in a manual / no-project mode for diagnostic purposes only. Do not run a machine in production without a verified project.
8. Re-initialize the absolute encoder (if used).
   • For EnDat or SSI absolute encoders, after the project is loaded and the drive is online, navigate to the encoder parameters (typically p0400 series and p0421 series) and execute the "Determine absolute encoder position" routine.
   • The routine is invoked by setting p1990 = 1 or by clicking "Absolute encoder adjustment" in STARTER. The drive will move the motor a small angle to capture the absolute position; ensure the mechanical system can tolerate this motion.
9. Verify the Technology Object configuration in SCOUT.
   • Open the affected axis / encoder TO (Encoder 0 in this case).
   • Confirm the encoder type, the encoder data set (EDS), and the reference to the SINAMICS Integrated encoder interface.
   • Recompile the TO configuration and load it to the device.
10. Save the project to the device non-volatile memory.
    • Use the menu Target system > Save to target system (or "Copy RAM to ROM" in SCOUT) so that the project survives the next power-down.

Verifying the Project Is Loaded and Healthy

After completing the recovery procedure, perform the following verification steps before returning the machine to production:

When the Project Cannot Be Uploaded

The source case notes that the project on the device is software-protected (no upload possible) and the user does not have a project archive on the service PC. This is a common situation when an OEM ships a machine with a locked project to protect intellectual property.

The legal / contractual path is to request the project archive from the OEM with the project password. Siemens support entry 99006251 describes the LED and diagnostic states but does not bypass project protection. Siemens does not provide a back-door to project passwords.

The technical paths when an OEM project is unavailable are:

• Parameter-by-parameter upload from the running device. Use SCOUT in online mode, then "Upload to PG" to retrieve a copy of the current project. If the OEM has set the know-how protection flag with a password, this upload will return a password-protected file.
• STARTER parameter upload for SINAMICS Integrated. STARTER can read the SINAMICS parameter set online; choose "Load to PG" to retrieve the parameter list. This is a low-level parameter file, not the SIMOTION project, but it allows the drive parameters to be re-applied after a new SIMOTION project is created.
• Complete re-commissioning. If neither path yields the project, the only option is to rebuild the project from scratch: create the TOs, configure the SINAMICS drive, set the PROFINET / PROFIBUS topology, and re-create the user program (ladder, ST, MCC charts). This requires the machine's PLC source code and the electrical drawing.

Common Adjacent Faults and Their Resolution

Preventive Measures for Long-Term Storage and Power-Down

To minimize the probability of a 20005 alarm or other boot-time fault after extended power-down, apply the following measures on machines that are stored, shipped, or seasonally used:

1. Store the machine with a controlled power-on cycle. At least once every six months, power the machine for 30 minutes so that the backup capacitors for the RTC and the diagnostic buffer stay charged and so that any latent SINAMICS configuration drift is surfaced and acknowledged.
2. Keep a recent project archive in a known location. After every engineering change, export the SCOUT project as a ZIP archive and store it on the machine's documentation server (or in the cloud). The archive contains the SIMOTION project, the SINAMICS parameter sets, and the HMI configuration.
3. Document the project password. Store the know-how protection password with the project archive in a secure location. Without the password, the archive cannot be opened for editing.
4. Maintain a factory reset image of the SIMOTION CF/MMC card. Image the card after final commissioning using a card reader and a disk imaging tool. This image can be restored to a new card if the card fails.
5. Record the PROFINET device name and IP for every controller. A printed label on the controller and a row in the machine's electrical drawing will save hours during commissioning.
6. For seasonal machines, schedule an annual re-commissioning that includes: project verification, firmware version check, drive parameter backup, safety function test, and battery replacement (where applicable).

Frequently Asked Questions