Replacing Siemens 1FK7063 Servomotor on SIMOTION D445 Systems

1. System Overview and Replacement Scenario

This reference covers the field replacement of a Siemens SIMOTION-controlled 1FK7 synchronous servomotor driving a SINAMICS S120 booksize axis. The configuration in question consists of:

The replacement raises two distinct engineering questions: (a) whether the MLFB suffix difference between 1FG2 and 1FG0 constitutes a topology mismatch, and (b) whether the encoder label change from A-2048 to AM22DQ F46 requires configuration changes in the SIMOTION SCOUT project.

2. MLFB Suffix Decoding for 1FK7063-5AF71

The Siemens MLFB (Machine-Readable Product Designation) for the 1FK7 family is structured as follows:

For 1FK7063 motors, the -1FGx suffix designates the integrated absolute encoder. The two most common variants on this frame size are:

• -1FG0: Absolute encoder, multi-turn, 22-bit resolution (AM22DQ), Drive-CLiQ interface
• -1FG2: Absolute encoder, multi-turn, 2048 sin/cos periods + EnDat2.2 (AS24DQI) or successor, Drive-CLiQ interface

Functionally both encoders are absolute multi-turn devices transmitting position over Drive-CLiQ. The difference is internal signal processing and resolution scaling, which is normally transparent to the application if the correct motor record is loaded in the drive object.

3. Encoder Identification: AM22DQ vs A-2048

The nameplate annotation on 1FK7 motors is often abbreviated differently by the factory depending on production batch. The two labels observed on the damaged vs. replacement motor decode as follows:

Both encoders are supported by SINAMICS S120 firmware V4.x and V5.x as standard motor encoder types for the 1FK7063 frame. The drive's automatic motor identification routine (Motor ID) detects the encoder type from Drive-CLiQ signaling during the initial commissioning handshake. No manual parameter change is normally required when the motor record is updated to match.

The label F46 on the AM22DQ typically refers to a Siemens-internal firmware index of the encoder electronics, not a customer-facing parameter. Mixed encoder batches within the same mechanical frame are normal field inventory.

4. SINAMICS S120 Topology and Drive-CLiQ Wiring

The Double Motor Module 6SL3120-2TE15-0AA3 occupies a single booksize slot and contains two fully independent drive channels. Each channel has its own Drive-CLiQ port (X200 / X201) on the front panel for the motor encoder feedback. The SIMOTION D445 connects to the Control Unit (CU320-2 or integrated D445) which daisy-chains the Motor Modules over Drive-CLiQ.

Typical topology for this machine:

5. Topology Comparison Levels

SIMOTION / SINAMICS performs a topology check at every ramp-up. The strictness of this check is controlled by parameter p9906 on the Control Unit and per-drive parameters p9907, p9908. Comparison levels are bit-coded:

To access these parameters in SCOUT, open the project, navigate to the affected drive object (Axis_1 / Servo_1), right-click and select Properties > Topology, then click Comparison Level. Alternatively, in the expert list of the drive (online), filter parameters starting with p9907 and p9908.

For routine field replacement of an identical-frame motor of the same series, Siemens service practice is to leave the comparison level at the project default and instead perform the steps in Section 7 so that topology is updated to the new hardware.

6. Prerequisites Before the Swap

1. Back up the SIMOTION project (project archive, .zip) to an external drive.
2. Back up the CF card image from the D445 using SIMOTION Scout's Target system > Load to file > Card image.
3. Record the current commissioning data of the affected axis (motor record, encoder data, p2000 reference speed, p2002 reference current, p2003 reference torque, p1531 power limit, p1545 vibration suppression).
4. Confirm the new motor's MLFB exactly matches what will be loaded into the project. If the nameplate reads 1FK7063-5AF71-1FG0, update the drive's motor record from 1FG2 to 1FG0 before download.
5. Ensure the SIMOTION D445 and SINAMICS S120 are de-energized, the 510 VDC link is discharged (p0897 or measurement at the DC link test points), and STO (Safe Torque Off) inputs are de-asserted.
6. Verify the replacement motor's holding brake option (here: without brake, digit 1) matches the original.

7. Step-by-Step Replacement Procedure

7.1 Mechanical and Electrical Removal

1. Lock out / tag out the cabinet mains and the 24 VDC logic supply.
2. Wait at least 5 minutes after power-down, then measure the DC link voltage at the Motor Module test points (DCP / DCN). Continue only when voltage is below 5 V.
3. Loosen the Drive-CLiQ connector on the motor's encoder port (an RJ45-style push-pull connector, dust cap if not reused).
4. Disconnect the power connector at the motor (size 1 power connector on 1FK7063).
5. Unbolt the motor from the machine flange. Note the orientation of the keyway or feather key if any.

7.2 Install the Replacement Motor

1. Mount the new 1FK7063 with the same shaft orientation. Tighten the flange bolts to the torque specified on the motor dimensional drawing (typically 25 Nm for SH 63, four M8 bolts).
2. Reconnect the power connector until the locking clip audibly engages.
3. Reconnect the Drive-CLiQ cable. The connector is keyed and will only seat in one orientation. Route the cable clear of moving parts.
4. Confirm the encoder ID on the new motor nameplate and compare with the project record.

7.3 Update the SCOUT Project (if MLFB suffix differs)

1. Open the SCOUT project offline.
2. In the project navigator, right-click the affected drive (e.g., Servo_1) and choose Properties.
3. In the Motor tab, change the motor selection from 1FK7063-5AF71-1FG2 to 1FK7063-5AF71-1FG0.
4. Accept the prompt to load the matching motor record (parameters p0300 through p0335, encoder parameters p0400 through p0431).
5. Compile the project (Project > Compile and check) and download to the target (Target system > Download) with the CPU in STOP.
6. Copy RAM to ROM (Target system > Copy RAM to ROM) so the updated topology persists across power cycles.

7.4 First Ramp-Up with the New Motor

1. Power up the system. The SINAMICS drives will perform the topology comparison on ramp-up.
2. Check the drive's diagnostic buffer (Commissioning > Diagnostics > Buffer) for any F01325 or F01326 alarms.
3. If F01325 appears, the topology mismatch is on the component MLFB; acknowledge and re-download after correcting the motor record.
4. Run the automatic motor identification routine: set p1910 = 1 on the affected drive, then issue a pulse enable. The drive will run a brief self-identification sequence with the motor.
5. If the encoder is absolute, perform the absolute encoder adjustment: set p2507 = 1 (commutation / encoder calibration), enable, and follow the on-screen prompts.
6. Back up the project to the CF card.

8. Verification Checklist

After commissioning, verify the following before releasing the machine to production:

9. Troubleshooting Matrix

10. SIMOTION D445 Specific Notes

The SIMOTION D445 is a high-performance motion controller with a built-in PROFIBUS / PROFINET interface and integrated SINAMICS S120 Control Unit functionality. Key facts relevant to this replacement:

• The D445 has its own DRIVE-CLiQ ports (X100, X101, X102) for direct connection of the booksize line-up. No separate CU320-2 is required.
• Firmware compatibility: SIMOTION V4.5 / V5.x with SINAMICS S120 V5.x is the supported combination for the 512 MB MultiAxes Package (CF card P-card variant 6AU1400-2PA00-0AA0 or higher).
• The MultiAxes Package license enables more axes per D445; standard licenses cap at fewer axes. Confirm the replacement axis is within licensed count.
• When downloading a new project, ensure the user program is consistent with the axis configuration; recompile all MCC / ST / LAD/FBD sources after motor record changes.

Refer to the official SIMOTION D445 manual (SIMOTION D4x5 Manual) and the SINAMICS S120 Function Manual (SINAMICS S120 Drive Functions) for parameter deep-dives.

11. Field-Proven Caveats

• When a 1FK7 motor is replaced with the same MLFB and the same encoder variant, no project change is required. The drive simply reports the new serial number; topology comparison will detect the change but no functional difference exists.
• When the MLFB suffix (e.g., 1FG0 vs 1FG2) differs, the safest practice is to update the project offline before reconnecting the new motor. Online "Adjust topology" only changes the topology entry, not the motor record parameters (p0300, p0301).
• If the spare motor has been on the shelf for several years, run p0341 = 1 (motor data identification, standstill) before p1910 = 1 to ensure the controller adapts to the actual stator resistance and inductance.
• Always back up the CF card after successful commissioning, not before. Restoring a pre-replacement image will re-introduce the topology mismatch.

FAQ