Resolving SINAMICS DRIVE-CLiQ Topology Inconsistency on CU305

Problem Overview

When commissioning or maintaining a SINAMICS S110 drive based on the CU305 Control Unit, engineers frequently encounter the online diagnostic message:

Information: The following devices are not consistent online: Drive_unit_1.
Information: Drive_unit_1: Uploading DRIVE-CLiQ set topology...
Information: Drive_unit_1: Uploading DRIVE-CLiQ actual topology...
Information: Drive_unit_1: Control_Unit: Drive object has been uploaded.
Information: Drive_unit_1: SERVO_02: Drive object has been uploaded.
Information: Drive_unit_1: Upload completed
Information: Project successfully loaded to the PG

The drive object (DO) Drive_unit_1 – typically the SERVO axis on the CU305 – is flagged in red in the project navigator inside StartDrive or STARTER, while sub-objects such as the Control Unit and the SERVO_02 drive object are highlighted in blue. The visual cue signals a topology inconsistency: the offline project's setpoint topology does not match the actual topology the drive is reporting through its DRIVE-CLiQ ports.

Even after the upload completes without a fault, the drive remains in commissioning mode, the status word reports Not Ready, and any run enable is suppressed. Two structural causes dominate this symptom class:

1. A synchronous servo motor without a DRIVE-CLiQ interface (or with one wired through an SMC30) was added to the project, but the online configuration has not been re-aligned to match the real hardware at the drive.
2. The drive still has p0010 ≠ 0 (commissioning filter active) so that the parameter changes required to adopt the actual topology cannot take effect.

DRIVE-CLiQ Topology Fundamentals

DRIVE-CLiQ is Siemens' proprietary digital ring/line interface that carries motor encoder data, temperature, electronic rating plate (EPR), and cyclic process data between components such as the Control Unit, Motor Modules, Line Modules, Sensor Modules, Terminal Modules, and motors with integrated electronics. Each CU305 has two DRIVE-CLiQ ports (X100, X101) plus a service port. See the SINAMICS S110 Commissioning Manual for the port map and the maximum node counts.

The CU305 evaluates actual topology vs. setpoint topology at every power-up and whenever p0009 / p0010 is changed. If a mismatch is detected, the drive raises alarm A01420 "Topology: comparison error" or fault F01300 "Topology error detected". The yellow/red colour in the StartDrive project tree corresponds to:

• Yellow: Component differs in firmware or article number but is functionally compatible.
• Red: Component is missing, unknown, or wrong type. Run enable is blocked.

Root Cause Analysis

The information line "The following devices are not consistent online: Drive_unit_1" is generated by the offline/online comparison after the upload. Use the following decision tree to localise the cause.

[Start: Drive_unit_1 inconsistent]
        |
        +--> Open "Topology" view in StartDrive
        |       |
        |       +--> All DRIVE-CLiQ nodes green? --NO--> Hardware/cabling fault
        |       |
        |       +--> SERVO_02 red? --YES--> Drive object mismatch (this article)
        |
        +--> Check r0002 operating display
        |       |
        |       +--> "Commissioning (p0010 != 0)" --YES--> Run commissioning exit
        |
        +--> Check motor type on SERVO_02
                |
                +--> Synchronous servo without DRIVE-CLiQ --YES--> Configure SMC30 path
                +--> Motor with DRIVE-CLiQ --YES--> Run "Configure DDS online" or "Upload device to PG"

The most common trigger observed in the field is a project built from a template that defaulted to a 1FK7 synchronous servo motor with a third-party SMC30 encoder interface. The actual hardware then presents either:

1. A motor with integrated DRIVE-CLiQ (e.g., 1FK7 with order suffix ...-1AHxx or 1FT7 with ...-1ACxx) that the project never references, or
2. An SMC30 module wired to a resolver / HTL / TTL encoder, while the project still expects DRIVE-CLiQ motor feedback.

In both cases the SERVO drive object's feedback configuration does not match what the CU305 reads on the encoder channel, so the comparison flags the drive as inconsistent.

Diagnostic Parameters and Status Codes

Connect StartDrive to the CU305 online and read the parameters in the following table to confirm the topology state. All parameter numbers reference the SINAMICS S110/S120 parameter list.

Fault code reference (subset):

• F01300: Topology error – component missing or unknown.
• F01320: Topology error – additional component on the DRIVE-CLiQ port that is not in the setpoint topology.
• A01420: Topology comparison – differences found (warning level, drive still operable once acknowledged).
• F08501: STOP via PROFIsafe / PROFINET – often appears when commissioning is still active and the controller denies the enable.

Resolution Path A – Automatic Online Configuration

Use the "Configure DDS online" or "Upload device to PG" workflow when the actual hardware is correct but the project was created from a template that did not match it. This is the recommended path for a motor with DRIVE-CLiQ interface.

1. Connect StartDrive (or STARTER) to the CU305 via PROFINET/PROFIBUS or Ethernet service interface.
2. Right-click Drive_unit_1 → "Upload device to PG" (or the equivalent icon in the toolbar).
3. StartDrive prompts: "Apply the actual topology as the new setpoint topology?" Click Yes. The CU305 writes the actual DRIVE-CLiQ node list into the project as the new setpoint.
4. Open Drive_unit_1 → Configuration → DDS and verify:
   • p0300 motor type code (e.g., 106 for 1FK7 without brake, 207 for 1FT7, 2 for non-Siemens synchronous motor).
   • p0301 motor code or order number – auto-filled from the EPR when the motor has DRIVE-CLiQ.
   • p0400 encoder type – must reference the correct encoder table (e.g., 2020 for DRIVE-CLiQ encoder with EPR).
5. If the parameter set is greyed out, set p0009 = 0 first; some StartDrive variants require a reset of the device access.
6. Save the project and download it back to the CU305 with "Download to device".
7. Run a warm restart (p0970 = 1 followed by power cycle) only if the topology compare level demands it.

After step 3, the warning indicators should switch from red to blue and r0127 should equal r0128.

Resolution Path B – Manual Offline Configuration with DRIVE-CLiQ Motor

Use this path when the engineering station is offline or when you want to lock down a known-good configuration before powering the cabinet.

1. In StartDrive, open the device view and double-click SERVO_02.
2. Select "Motor with DRIVE-CLiQ Interface" from the feedback selection list (StartDrive → Drive → Configuration → Feedback → "Motor with DRIVE-CLiQ").
3. Choose the motor article number from the selection list. StartDrive auto-loads the following from the motor's electronic rating plate when the drive next powers up:
   • p0300 motor type
   • p0304, p0305 rated voltage / current
   • p0307 rated power
   • p0311 rated speed
   • p0314, p0315 pole pair number, pole pair distance
4. Set p0010 = 1 (quick commissioning), enter the application limits (p0640 current limit, p1082 max speed, p1520/p1521 torque limits), then return to p0010 = 0.
5. Save RAM to ROM (p0971 = 1) and download the project to the drive.
6. Cycle power on the CU305. On boot, the drive reads the EPR from the DRIVE-CLiQ motor and verifies against the setpoint topology.

Exiting Commissioning Mode (p0010 = 0)

Even with a correct topology, the drive stays "Not Ready" as long as p0010 is non-zero. The common pitfall is the following sequence:

1. Engineer uploads the project from the CU305.
2. Online change made to a parameter such as p0301 – StartDrive automatically sets p0010 = 1.
3. After the upload, the engineer never sets p0010 = 0, so the drive remains in commissioning filter and rejects enable commands.

Procedure to exit commissioning:

1. In StartDrive online, navigate to Drive_unit_1 → Commissioning → Commissioning wizard.
2. Complete (or skip) the wizard – it writes the correct values into p0010 and p0009.
3. If the wizard is unavailable, enter the parameter table and set:
   • p0009 = 0 (Device commissioning – device configuration)
   • p0010 = 0 (Ready)
4. Save the parameter set with p0971 = 1.
5. Read r0002; the operating display must read "Operation – ready for switching on" or similar.

SMC30 Encoder Interface Configuration

If the actual hardware uses an SMC30 Sensor Module Cabinet-Mounted (article number 6SL3055-0AA00-5CA2 for the standard variant), the project must reference the SMC30 explicitly and the motor feedback path is no longer DRIVE-CLiQ. The SMC30 supports HTL/TTL encoders up to 1 MHz and resolvers via the relevant variant.

When the SMC30 is used, the topology comparison now expects two DO types on the relevant DRIVE-CLiQ port:

• The SERVO drive object configured for SMC30 feedback, and
• The SMC30 itself as a separate component.

Verify r0128 lists the SMC30 with the correct article number. A common field fault is the SMC30 inserted on a DRIVE-CLiQ port that the SERVO drive object is not using for feedback (e.g., X100 instead of the configured X101). Re-routing the DRIVE-CLiQ cable resolves the inconsistency.

Factory Reset Procedure (CU305)

If the project is unrecoverable, perform a factory reset on the CU305 and start the commissioning from a clean slate. Always back up the existing project before issuing a reset.

1. Connect the PG to the CU305. Verify the drive is in "Operation – ready for switching on" or stop state; never reset a drive currently in motion.
2. In the parameter table set p0010 = 30 (factory reset).
3. Set p0970 = 1 to trigger the factory reset. The CU305 returns r3996 = 1 when the reset is in progress and clears all drive parameters to factory defaults.
4. Wait until the CU305 re-boots automatically. The DRIVE-CLiQ ports remain active and the actual topology is re-read.
5. After the reset, drive object types revert to "unconfigured". Re-run the StartDrive commissioning wizard from scratch.
6. If the reset does not complete because of a parameter write lock, check p7763 (write protection) and p7762 (know-how protection) and clear them as necessary.

Verification and Commissioning Sign-Off

Run the following checklist before signing off the drive as "ready".

1. Project navigator: no red indicators on any device. Yellow is acceptable if documented.
2. r0002 = "Operation – ready for switching on" or "Operation – switching on inhibited".
3. p0010 = 0, p0009 = 0.
4. r0127 = r0128. Capture both parameter dumps and attach to the FAT/SAT report.
5. r0945[0...7] and r2122[0...7] = 0 (no active faults or alarms).
6. Status word r0899 bit 0 = 1 (control requested) when PLC issues STW1 bit 0; bit 1 = 1 when PLC pulses enable.
7. Run a controlled motion test (10 % of rated speed, 1 second) and verify r0061 (rotor position) and r0021 (smoothed speed) follow the setpoint without overshoot.
8. Save the project to the engineering server and to a CF card if the CU305 supports it.

Quick Reference – Topology Inconsistency Matrix

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