Resolving SIMOTION D Fault 20005: SINAMICS Drive Diagnostics

Resolving SIMOTION D Fault 20005: SINAMICS Drive Cause Diagnostics

SIMOTION D controllers integrate a SINAMICS drive section and a SIMOTION motion-control section on a single hardware platform. When the integrated SINAMICS section reports a fault, SIMOTION surfaces it as alarm 20005 with an additional reason code that points to the originating SINAMICS fault category. Because alarm 20005 only indicates that a drive problem exists—not which drive fault it is—the alarm is widely regarded as the weakest single diagnostic indicator in the Siemens motion-control stack. This reference details the structure of alarm 20005, the meaning of the reason codes observed in field cases (200h, 4h, 220h, 5h), and the systematic procedure for mapping each reason code to a root-cause SINAMICS F-code.

1. Overview of Alarm 20005 in SIMOTION D

Alarm 20005 belongs to the SIMOTION technology-object (TO) alarm class. It is generated whenever one of the following conditions occurs on an axis, encoder, or output cam TO whose drive interface (SINAMICS Integrated, SINAMICS S120 CU320, or CX32-2 controller extension) reports an internal fault:

• Drive fault forwarded from the SINAMICS drive object (DO) of type SERVO, VECTOR, or VSA.
• Encoder fault on a connected motor encoder or external encoder.
• PROFIdrive sign-of-life failure between SIMOTION and the SINAMICS DO.
• Safety-integrated fault on the SINAMICS drive that requires STO/SS1.
• Power-unit or supply fault at the SINAMICS Line Module or Motor Module.

Alarm 20005 is, by itself, a container. The reason code is what tells you which of the above categories is active, and from there you must consult the SINAMICS diagnostic buffer to find the specific F-code (e.g., F07900, F30021, F30895) that identifies the actual hardware or software cause.

2. Reason Code Interpretation Table

The reason codes reported in the field incident—200h, 4h, 220h, and 5h—are SIMOTION-side classifiers. They do not map one-to-one to the underlying SINAMICS F-code; they tell you the TO-level failure mode that was detected. The mapping below reflects the categories documented for the SIMOTION TO alarm subsystem. Always confirm the exact mapping against your installed Siemens Industry Online Support entry for the alarm (search for alarm 20005 in the SIMOTION SCOUT help system or the SIMOTION Diagnostics Manual).

3. Why Alarm 20005 Looks "Useless" in the Field

Alarm 20005 is intentionally a low-information pointer alarm. From the SIMOTION runtime perspective, only the following are visible at the moment the alarm is raised:

• Which drive DO raised the alarm (DO number and logical address).
• Which status-word bit set (typically bit 3 or bit 0 of ZSW1, depending on the SIMOTION version).
• Which TO subclass is affected (axis, encoder, output cam, cam track).

What alarm 20005 does not tell you:

• The underlying SINAMICS F-code (F0xxxx, F2xxxx, F3xxxx, F6xxxx).
• The SINAMICS diagnostic buffer entry that contains timestamps and the originating parameter value.
• The active warning status of the drive.
• The STO/SS1 state if the fault is safety-related.

This is why field engineers consistently report the alarm as "absolutely useless" without further drill-down. The professional diagnostic workflow is to either connect a programming laptop with SIMOTION SCOUT / TIA Portal, use the IT-Diag web server, or expose the SINAMICS fault buffer to the operator HMI.

4. Drilling Down: SIMOTION SCOUT / TIA Portal Procedure

The authoritative drill-down procedure uses the engineering tool to read the SINAMICS diagnostic buffer attached to the drive DO that raised alarm 20005.

4.1 Prerequisites

• SIMOTION SCOUT TIA (or SIMOTION SCOUT V5.x for older projects) installed on an engineering station.
• Project file (.zip or .zap) for the affected machine accessible, or online access via the controller's IP address.
• PG/PC Ethernet cable connection to the X120 service port of the SIMOTION D4x5, or to the X127 port for D410/D4xx-2.
• Appropriate access level (operator / service / manufacturer) on the SINAMICS DO. Default service password: SINAMICS.

4.2 Step-by-Step drill-down

1. Go online to the SIMOTION D controller. Right-click the project node and select Connect to target system > Ethernet.
2. Once online, open the Diagnostics perspective. Expand the drive DO whose logical address matches the alarm entry (in the incident: 262 decimal).
3. Right-click the SINAMICS DO and choose Diagnostics > Drive diagnostics (in SCOUT) or Online & Diagnostics > Diagnostic buffer (in TIA Portal).
4. Read the SINAMICS diagnostic buffer (parameter r0947[0..63] for fault codes, r0948[0..63] for fault value, r0949[0..63] for component). Each buffer entry includes the SINAMICS fault number (F-code), the time of occurrence, and the value that triggered it.
5. Cross-reference the F-code in the SINOTION / SINAMICS List Manual. The List Manual entry describes cause, remedy, and acknowledgement requirements.
6. Capture the F-code and associated parameter values before clearing the buffer; clearing requires an explicit "Clear fault" on the DO or a power-cycle of the SINAMICS section, depending on the fault class.

5. IT-Diag Web Server (No Laptop at the Machine)

SIMOTION D controllers ship with an integrated IT-Diag (Information Technology Diagnostics) web server. IT-Diag exposes the SINAMICS diagnostic buffer, the SIMOTION diagnostic buffer, the system event log, and the active alarms directly to a browser.

5.1 Enabling and accessing IT-Diag

1. Open SIMOTION SCOUT, go online to the controller.
2. Right-click the SIMOTION D node > Webserver > Activate (or confirm the HTTPS port).
3. From any browser on the same network, navigate to https://<controller-IP>:8443 (HTTPS, default port 8443). HTTP may also be enabled on port 8081 in older firmware.
4. Authenticate with the controller's access password (same user level used in SCOUT).

5.2 Reading the fault buffer through IT-Diag

1. From the IT-Diag home page, select the drive DO associated with logical address 262.
2. Open the Diagnostic buffer panel. The page renders the same entries as parameter r0947[0..63].
3. Record the top-most (most recent) F-code, its value, and the timestamp.
4. Use the F-code to navigate to the List Manual entry for root cause and remedy.

IT-Diag has been available for more than a decade and is the recommended path when no SIMOTION SCOUT license is available at the customer site or when the engineer is remote.

6. HMI Integration: Forwarding SINAMICS Faults to the Operator

The most production-friendly approach is to forward SINAMICS faults directly to the machine HMI so that operators and remote support engineers see the underlying F-code rather than the SIMOTION-only 20005. Two methods are documented and field-proven.

6.1 ReadDriveFaults / ReadDriveParameter functions

SIMOTION exposes the system functions _readDriveFaults(...) and _readDriveParameter(...) for use in MCC (Motion Control Chart) or ST (Structured Text) units. These functions read the SINAMICS diagnostic buffer of a referenced DO at runtime.

// ST pseudocode: read latest SINAMICS fault from DO #1 (logical address 262)
VAR
    faultBuffer : ARRAY[0..63] OF DINT;
    faultCount  : DINT;
    i           : INT;
END_VAR

// _readDriveFaults returns fault buffer of the drive attached to the axis
faultCount := _readDriveFaults(
                 axis := TO_Axis_DriveName,    // axis TO with Drive DO reference
                 faultNumberArray := faultBuffer);

// faultBuffer[0] contains the most recent fault number (F-code)
// faultBuffer[1] contains the associated fault value

Wire the function call to an HMI tag (e.g., a 64-element array of DINTs) and visualize the array on the alarm page. Operators see the actual F-code without needing engineering credentials.

6.2 TIA Portal V4.5 automatic forwarding

As of TIA Portal V17 (the "V4.5" generation discussed in the field discussion), the SINAMICS alarms can be configured to automatically forward to the HMI alarm log when the SIMOTION project uses unified alarm handling. This eliminates the need for a custom ReadDriveFaults call in many applications. Enable it in the device configuration of the SINAMICS DO under Properties > Alarms > Automatic forwarding to HMI and ensure the HMI is bound to the alarm subscription in the project tree.

7. Systematic Resolution Procedure

The following procedure consolidates the steps above into a single decision flow that any field engineer can execute.

7.1 Capture the alarm context

1. Record the alarm number (20005), reason code, logical address, encoder number, and TO number from the HMI or SIMOTION diagnostic buffer.
2. Record the axis name and the time of occurrence.
3. Determine whether the fault is reproducible (does the axis always fault within N seconds?) or stochastic.

7.2 Map the reason code to a category

1. Use Section 2 of this article to classify the reason code.
2. For reason 200h or 220h (encoder-related), focus on encoder wiring, screen bonding, DRIVE-CLiQ fiber-optic integrity, and the parameter set of p0400–p0430 in SINAMICS.
3. For reason 4h (PROFIdrive), focus on cyclic bus health, telegram configuration consistency between SIMOTION and SINAMICS, and PROFINET / PROFIBUS diagnostics.
4. For reason 5h (drive-side safety or control), focus on Safety Integrated parameters p9601 ff., STO wiring, and TM54F if installed.

7.3 Read the SINAMICS diagnostic buffer

1. Use SCOUT / TIA Portal (Section 4) or IT-Diag (Section 5) to read the SINAMICS buffer.
2. Identify the most recent F-code and its associated fault value.
3. Consult the SINAMICS List Manual for that F-code.

7.4 Apply the documented remedy

1. Follow the List Manual remedy for the F-code (mechanical check, wiring fix, parameter change, firmware update, replacement).
2. Document every change made before clearing the buffer.
3. If the F-code is repeatable, add it to the device logbook for later trend analysis.

7.5 Clear and verify

1. Reset the SINAMICS faults (DO command: "Clear faults", or set p3981 = 0 → 1 for factory-reset-style acknowledge, depending on fault class).
2. Run the axis in jog mode for several cycles; confirm no faults recur.
3. Place the axis into automatic and run a representative motion profile; confirm no faults recur.
4. Update the machine's fault list and HMI display so the F-code is visible at the operator level.

8. Field-Proven Diagnostic Matrix

9. Verification and Acceptance Test

After applying the remedy, the following verification matrix confirms the fault is closed.

10. Preventive Measures and Best Practices

1. Always expose the SINAMICS fault buffer to the HMI. A custom HMI page that displays _readDriveFaults() results eliminates the "20005 with no info" scenario entirely. This is the single most valuable preventive measure.
2. Use IT-Diag as a permanent diagnostic landing page. It is browser-based, requires no license, and is available on every supported SIMOTION D controller.
3. Enable automatic SINAMICS-to-HMI alarm forwarding when running on TIA Portal V17 or later. This eliminates the need for custom function blocks and gives operators a unified alarm stream.
4. Standardize on DRIVE-CLiQ cabling discipline. A large fraction of reason 200h and 220h faults originate from contaminated, kinked, or improperly seated DRIVE-CLiQ fiber-optic cables. Mandate torque-controlled DRIVE-CLiQ connector seating during commissioning.
5. Capture axis logbooks during commissioning. SIMOTION axis logbooks (non-volatile parameter axisLogbookDrive and the SINAMICS diagnostic buffer) should be exported and stored with each machine's as-built documentation. Trend them on annual service visits.
6. Plan a migration path. Because SIMOTION is in announced phase-out, customers should plan migration to the Siemens motion-control successor platform. Confirm the latest lifecycle dates on the SIMOTION product page and align the migration with the next major machine rebuild.
7. Document the mapping between SIMOTION alarm reason codes and SINAMICS F-codes for each machine class. A laminated card on the cabinet door turns a 30-minute remote support call into a five-minute call.

11. Common Edge Cases

11.1 Fault appears only during emergency stop

If alarm 20005 with reason 5h appears only after emergency stop, the cause is usually Safety Integrated STO/SS1 response. Verify p9652 (SI Safe Stop 1 time) and the STO wiring to the safe input. Confirm that the wiring is consistent with the safety mode selected in SCOUT (SINAMICS Safety Integrated Extended Functions).

11.2 Fault appears only when ambient temperature rises

Reason 200h or 220h faults that are temperature-correlated usually point to an encoder that is drifting, an SMC/SME module with marginal thermal margin, or a motor thermal model trip. Capture the SINAMICS diagnostic buffer at the time of fault and read r0035[0] (motor temperature) and r0037[0] (power section temperature). If the values exceed p0605 or p0614, the motor or module is undersized for the duty cycle.

11.3 Fault appears after firmware update

When SINAMICS or SIMOTION firmware is upgraded, the default parameter set may reset the encoder configuration (p0400), the Safety Integrated mode (p9601), or the cyclic I/O configuration. Re-run the commissioning wizard for the affected drive DO after any firmware upgrade and compare the parameter dump against the project backup.

11.4 Fault appears only at high speed or high torque

Reason 200h at high mechanical speed often traces to an encoder cable shielding problem (high dV/dt injection into the encoder signal). Replace encoder cable with a Siemens pre-fabricated cable with continuous shield and 360° bonding at both ends. Reason 5h at high torque may indicate a peak-current shutdown from the motor module; verify r0030 against the peak current rating of the Motor Module.

12. Related SIMOTION Drive Alarms

Alarm 20005 is the most common drive-related alarm, but the following alarms occur in the same family and benefit from the same drill-down procedure:

13. Frequently Asked Questions