SINAMICS G150 TM31 Replacement: Resolving F01325 Topology Fault

Problem Summary

Field reports confirm that swapping a SINAMICS Terminal Module TM31 with MLFB 6SL3055-0AA00-3AA0 for the current production successor 6SL3055-0AA00-3AA1 on a SINAMICS G150 cabinet drive raises fault F01325 "Topology: Component number not present in target topology" at the first POWER ON. Depending on the Control Unit firmware version, the same swap can additionally present F01352 "Topology: Unable to determine actual topology" during the initial DRIVE-CLiQ enumeration. Because the G150 stores its commissioned topology on the removable memory card of the Control Unit, the new TM31 is detected on the DRIVE-CLiQ ring but its component identification no longer matches the part number recorded during the original commissioning.

Resolution does not require replacing the module, changing the wiring, or modifying the project. It requires a topology reconciliation in which the drive accepts the -3AA1 module as the new reference for that DRIVE-CLiQ port. The drive does not "fail" because the TM31 hardware is defective - it fails because the component number parameter (most often p0151) still expects the previous -3AA0 identification.

TM31 Module Identification and Hardware Variants

The SINAMICS Terminal Module TM31 is a digital and analog I/O expansion module that connects to a SINAMICS drive through a DRIVE-CLiQ link. It provides 8 dedicated digital inputs, 4 bidirectional digital inputs/outputs, 2 differential analog inputs, 2 analog outputs, 1 KTY/PT1000 temperature sensor input, 1 relay output, and 1 dual-port DRIVE-CLiQ interface for daisy-chaining additional components. The TM31 is commonly used inside a G150 cabinet to bring customer terminal signals into the drive and to provide them back as control commands.

Both variants expose the same connector layout, the same 24 V wiring pattern, the same I/O count, the same firmware upgrade path, and the same STARTER/Startdrive project representation. What differs is the DRIVE-CLiQ component identification stored inside the module. SINAMICS treats every detected DRIVE-CLiQ node as a uniquely addressable component, identified by part number plus serial number, so a TM31 with a different MLFB looks like a different device to the topology engine.

For full identification of the currently shipped MLFB, refer to the Siemens Industry Online Support entry for the SINAMICS TERMINAL MODULE TM31 - 6SL3055-0AA00-3AA1. Detailed parameter lists are published in the SINAMICS S120/S150 List Manual (Function Manual FH1), which also applies to the G150 product family.

SINAMICS G150 System Architecture and DRIVE-CLiQ Topology

The SINAMICS G150 is a cabinet-built, air-cooled or water-cooled low-voltage AC drive based on the SINAMICS S120 control architecture. The control chassis contains:

• One Control Unit (typically a CU320-2 DP or CU320-2 PN, depending on the fieldbus interface)
• One or more Line Modules (Active Line Module or Smart Line Module)
• One or more Motor Modules
• One or more Sensor Modules (SMC10/SMC20/SMC30/SME20/SME25/SME120) for motor encoders
• Optional Terminal Modules (TM31, TM15, TM17, TM41, TM54F) for I/O and safety expansion

All modules are interconnected via DRIVE-CLiQ, a Siemens-proprietary serial interface running over shielded RJ45 patch cables. Each DRIVE-CLiQ node carries a unique 7-byte component identifier consisting of the Siemens part number, the manufacturer code, and the unique serial number of the device. This identifier is what the Control Unit uses to validate the actual (detected) topology against the configured (target) topology that was stored on the memory card during commissioning.

DRIVE-CLiQ port allocation on a typical G150

On a standard single-motor G150 cabinet, the Control Unit's DRIVE-CLiQ ports are factory-wired as follows:

• Port X100 of CU320-2 to Line Module
• Port X101 of CU320-2 to Motor Module
• Port X102 (or X103) routed to the customer terminal compartment where the TM31 (and optionally a Sensor Module for the motor encoder) is wired

The STARTER/Startdrive topology view will therefore display, in order, the CU drive object, the Line Module drive object, the Motor Module drive object, and one TM31 drive object assigned under the Control Unit. If the cabinet includes a SMC or an additional TM41, additional drive objects will appear in the topology.

Why DRIVE-CLiQ port assignment matters during a swap

The TM31 has two DRIVE-CLiQ jacks: X500 and X501. X500 is the upstream port (toward the Control Unit). X501 is the downstream port (toward additional chained components). If a service engineer inadvertently lands the upstream cable on X501, the topology engine will detect the module at the wrong logical address and F01325 will reappear every POWER ON, even after p0151 has been reassigned. Always confirm cable seating before opening STARTER.

Fault Code F01325 - Detailed Analysis

F01325 is the canonical "topology mismatch" fault for the SINAMICS drive family. The SINAMICS S120/S150 List Manual (FH1) defines it as follows:

When r2124 displays a value such as 3 or 4, the value corresponds to the component number the drive believes should exist. Cross-reference this against the actual topology by reading r0095 (component number actual value) for each drive object, or by opening the topology view in STARTER/Startdrive.

Why F01325 fires after a TM31 swap

The Control Unit's target topology is reconstructed from the project stored on the memory card. When the project was first commissioned, the -3AA0 TM31 was inserted, identified by its DRIVE-CLiQ serial number, and assigned to drive object number N (commonly DO 3 or DO 4 on a single-motor G150). That assignment is stored in two locations:

1. The drive's project file on the memory card (the offline image)
2. Inside p0151 for the TM31 drive object (the online parameter)

When the -3AA1 module is installed, the Control Unit detects the new module at the same DRIVE-CLiQ port. The component detection routine reads the new module's identification and concludes "this is a different device than what p0151 expects." F01325 fires with r2124 holding the expected (old) component number.

Fault Code F01352 - Detailed Analysis

F01352 is the secondary topology fault that surfaces immediately after the swap on firmware versions that aggressively validate component identification during first boot.

The "Unknown component ID" cause is the one that applies to the -3AA1 swap. If the Control Unit cannot parse the identification block of the new TM31 - for example because the Control Unit firmware predates the introduction of the -3AA1 module - it raises F01352 in addition to F01325. The fix is to either (a) update the Control Unit firmware to V4.5 SP3 or later, or (b) force the topology to learn the new module through STARTER or Startdrive.

Topology Parameter Map

The SINAMICS topology uses a multi-level parameter hierarchy. The parameters below are the ones most relevant to a TM31 swap on a G150.

The typical p9907 sequence is: set p9908 = 1 (use actual as reference), set p9904 = 1 (start comparison), set p9907 = 1 (copy target to actual) or p9907 = 2 (copy actual to target). After this sequence, perform a POWER ON for the new topology to take effect.

Root Cause Analysis

The root cause is not a hardware defect in the -3AA1 module. Both -3AA0 and -3AA1 are functionally equivalent at the I/O level. The fault is a topology identity mismatch that occurs because:

1. The G150 was commissioned with a project stored on the memory card that includes the -3AA0 TM31's DRIVE-CLiQ identification.
2. When the new -3AA1 module is connected, the Control Unit's automatic topology detection routine recognizes a component on that port but reports a different ID than the one expected by p0151.
3. The drive's commissioning consistency check triggers F01325 (and sometimes F01352), preventing normal drive operation.

This is by design. SINAMICS protects the drive against inadvertent topology changes that could affect safety functions, encoder evaluation, or parallel drive configurations. A TM31 swap is treated the same way as a Motor Module swap would be. The user's original post is consistent with this: the TM31 works electrically (LEDs, wiring, customer terminal strip are identical) but the drive refuses to bring it into the topology.

Resolution Procedure - Step by Step

Use the following procedure to bring a SINAMICS G150 with a newly swapped TM31 module (-3AA1) back into service. The procedure assumes STARTER V5.x (or later) or Startdrive V15 (or later) is installed on the engineering PC, with Ethernet access to the G150 Control Unit through the X127 service interface.

Prerequisites

• STARTER V5.x or Startdrive V15 installed on the engineering PC
• Ethernet connection to the Control Unit (X127 service interface at 192.168.0.2/24, default address) or PROFIBUS connection via the CU320-2 DP
• The original commissioning project (DCP file or TIA Portal archive) - strongly recommended
• Backup image of the memory card contents
• Drive password (and Safety password, if Safety Integrated is enabled)

Procedure

1. Confirm the swap mechanically: power down the G150 cabinet, lock out per local safety rules, open the cabinet door, and verify the TM31 module on the customer terminal strip is the -3AA1 variant. The MLFB label is on the front face of the module.
2. Check the DRIVE-CLiQ wiring. The TM31 has two DRIVE-CLiQ ports: X500 (upstream, toward the Control Unit) and X501 (downstream, for chaining). Confirm the cable from the Control Unit's assigned port lands in X500 of the new TM31. A swapped cable causes F01325 regardless of module identity.
3. Power the cabinet back on. Observe the TM31 status LED using the table below.

4. Read the active faults from the Control Unit via the basic operator panel (BOP20) or AOP30: navigate to Menu > Diagnostics > Active faults and confirm F01325 (and possibly F01352). Record the alarm value in r2124.
5. Connect STARTER or Startdrive to the Control Unit and go online. STARTER connects via TCP/IP to 192.168.0.2 by default. Startdrive uses the TIA Portal device discovery.
6. In the project navigator, expand the Control Unit and click Topology. The actual topology view shows the new TM31 as a "different" component (yellow or red marker) compared with the target topology.
7. Right-click the TM31 in the topology view and select Assign component number, or directly edit p0151 for that TM31 drive object to match the detected component number shown in r0095 for that DRIVE-CLiQ port.
8. Save the project to the engineering PC, then download the updated topology to the drive's memory card using STARTER Download to target device or Startdrive Load to device.
9. Perform a POWER ON reset on the cabinet (control voltage off, wait 30 seconds, control voltage on). The main power may remain off during this step.
10. Reconnect STARTER/Startdrive. Verify the topology view shows the TM31 in green (consistent) for all DOs.
11. Acknowledge the F01325 (and F01352, if present). F01352 requires a POWER ON acknowledge; the cycle in step 9 satisfies this.
12. Run a no-load motor identification (p1910) only if the drive was de-energized long enough to require a re-tune, otherwise perform a basic function test: enable drive, ramp motor to a low speed, ramp back, disable. Confirm no F-class faults.

If the original project is not available

The original post mentioned "There is only hard copy," indicating the user did not have an electronic backup of the commissioning project. In this scenario, the standard procedure becomes:

1. Upload the current project from the drive to the engineering PC using STARTER Load to PG or Startdrive Upload from device. The tool reads out the current memory card contents and creates a project file.
2. Go online and use the topology wizard (or manual edit of p0151) to accept the new TM31 component.
3. Save the recovered project, then download it back to the memory card to confirm the topology is consistent.

STARTER and Startdrive Configuration

Both STARTER and Startdrive handle the TM31 topology reconciliation. The differences are mostly user interface.

In STARTER, the menu sequence is Configuration > Topology > Component number. Double-click the TM31 entry to edit p0151 directly, or right-click and choose Assign component number from actual topology. After the assignment, click Save and compile, then download to the memory card. After the next POWER ON, the topology is consistent and F01325 / F01352 will not reappear.

In Startdrive, the Device configuration view shows the actual versus target topology side by side. Press the Compare button to highlight mismatches, then click Adopt to accept the new TM31 as the actual topology. Compile and download as in STARTER.

Memory Card and Project Backup

The SINAMICS G150 stores its firmware, parameters, and topology on a removable CompactFlash card on the Control Unit. The card carries the MLFB 6SL3056-0AA00-6AA0 or a higher suffix. Before any topology change:

1. Pull the memory card from the Control Unit and image it on a PC using a CompactFlash card reader. Field engineers commonly use the SIMATIC Automation Tool, Win32 Disk Imager, or the DOS-level dd command to create a byte-image.
2. Label the image with the drive serial number and the date of the change. Keep at least one known-good image offsite.
3. Perform the topology reconciliation against the live card, but verify against the backup image if anything goes wrong.

If the only backup available is the on-card copy (the "hard copy" referenced in the original post), proceed by uploading the project from the drive first, as outlined in the prior section. Do not reformat the memory card without first confirming that all parameters have been archived elsewhere - a reformat erases both the firmware and the commissioning project.

Verification and Commissioning Tests

After the topology reconciliation, perform the following verification sequence:

1. POWER ON cycle with control voltage only; observe the TM31 status LED transitioning from GREEN flashing to GREEN steady within about 30 seconds. A persistent GREEN flash or RED indication means the topology is still inconsistent.
2. Read r9771 (commissioning status word). Bit 0 should indicate "drive ready," bit 1 should indicate "drive commissioning complete." If bit 4 (safety commissioning complete) is set, the Safety Integrated parameters were preserved.
3. Read r0002 (drive operating display). The display should show the configured drive status, not "Topology fault."
4. From STARTER/Startdrive, run the Control checks routine under Diagnostics > Trace if a deep verification is required. The trace records the I/O response of the new TM31 over time.
5. Verify the digital inputs (TM31 DI 0..11) and outputs (DO 0..3) respond to field wiring. The default mapping is documented in the TM31 List Manual.
6. Verify the analog inputs (AI 0, AI 1) and outputs (AO 0, AO 1) match the configured scaling: p4056, p4057, p4058, p4059 for the inputs; p4071, p4072 for the outputs.
7. Run the motor in test mode at low speed (5 to 10 RPM) for 30 seconds, then ramp to nominal speed and back. Confirm no F-class faults and no A-class warnings.

Field-Proven Caveats and Edge Cases

1. Firmware version dependency

Some G150 Control Units shipped before 2018 run firmware V4.x or V5.x. The -3AA1 TM31 module is supported on firmware V4.5 SP3 and later. If your CU320-2 is on V4.4 or earlier, the new module's identification block may not parse correctly, triggering F01352 even after p0151 has been updated. Update the Control Unit firmware via the memory card or Web server (SINAMICS Web Server) before continuing.

2. Mixed topology modules

If the G150 has both a TM31 and a TM15 (or TM41, or TM54F), only the swapped module needs reassignment. Do not edit p0151 for the unaffected module.

3. Safety Integrated considerations

If the drive uses PROFIsafe or TM54F, the Safety Integrated parameters require a Safety password to download. After the TM31 swap, accept the new topology, then execute the safety commissioning sequence (online Safety password, accept, save) before the safety functions will pass their self-test.

4. STARTER version compatibility

STARTER V4.x cannot open project files created by STARTER V5.x or Startdrive. If the original commissioning was done with an older STARTER version, install the matching version on the engineering PC or upgrade the project.

5. Offline commissioning trap

Some field engineers attempt to download the original project file without going online first. This works for parameter values but does not change p0151 if the project was not opened in STARTER and recompiled. Always recompile after any topology-relevant change.

6. Module seating

The TM31 module snaps onto a DIN rail inside the customer terminal compartment. The wiring harness to the cabinet's customer terminals is usually keyed. If the new module is not seated properly, the DRIVE-CLiQ link can be intermittent, causing F01325 to reappear at random intervals even after the parameter has been updated. Reseat the module firmly.

7. Memory card swap

If the memory card has been swapped independently of the TM31, the firmware stored on the card may not recognize the -3AA1 module. Always swap the memory card back to the original, or use a card that was imaged from the original card.

8. Multiple cabinet installations

If the G150 cabinet is part of a multi-drive line-up (for example, a paper machine section with five G150 cabinets), a TM31 swap on one cabinet does not affect the others. The topology reconciliation is local to that Control Unit.

Troubleshooting Matrix

Frequently Asked Questions