SIMOTION Phase-Out: Migrating D and C to S7-1500 T-CPU

Overview of the SIMOTION Phase-Out

Siemens has formally announced the phase-out of the SIMOTION Motion Control System, including the SIMOTION D controller platform, the SIMOTION C integrated PLC, the SIMOTION P PC-based controller, the SCOUT engineering environment, and the SIMOTION firmware (Kernel) versions V4.5, V5.1, V5.2, and V5.3 with all associated service packs and hotfixes. The phase-out of SIMOTION D was announced on October 1, 2025, and a parallel phase-out of the SIMOTION C product line set PM400 (product phase-out announcement) on October 1, 2023 with PM410 (discontinuation) effective October 1, 2024.

The successor architecture is the S7-1500 with Technology CPUs (T-CPU) and the SINAMICS drive family, configured entirely inside TIA Portal. This reference documents the affected product families, the phase-out milestones, the architectural differences between SIMOTION and the S7-1500 T-CPU, and the engineering pattern for migrating complex motion applications (MCC charts, Motion Tasks, camming, gearing, path interpolation) to a TIA Portal environment using the LAxisCtrl technology library.

Affected Product Families and Firmware Versions

Phase-Out Milestone Definitions

Siemens uses a two-step Product Management (PM) milestone pattern for lifecycle announcements. Engineers must read these correctly to plan replacement and spare-part inventory.

SIMOTION Architecture Recap (Pre-Phase-Out Reference)

SIMOTION was structured as a layered runtime on top of SINAMICS drives. Understanding the layering is critical because TIA Portal / S7-1500 T-CPU does not preserve every layer as a discrete object — some responsibilities collapse into the Technology Object (TO) of the S7-1500, and others must be re-implemented in user code or imported as a library.

1. Drive layer: SINAMICS S120 / S210 / G120 with parameter sets, BICO interconnections, and DO (Drive Object) configuration in STARTER or Startdrive.
2. Controller layer: SIMOTION D / C / P runs the real-time kernel; TO (Technology Object) for Axis, Cam, Path, Synchronization, Following Object, Cam Ext.
3. Programming layer: SCOUT with MCC (Motion Control Chart), ST (Structured Text), LAD/FBD, plus Motion Tasks and the MCC command library.
4. Communication layer: PROFINET IRT / PROFIBUS DP for drive telegram types (Standard Telegram 1, Siemens Telegram 105, 106, 116, 125, 136).

The S7-1500 T-CPU absorbs the drive and controller layers in the TO. The programming layer is replaced by TIA Portal STEP 7 with PLC Open motion blocks (MC_Power, MC_MoveAbsolute, MC_CamIn, MC_GearIn, MC_Interpolate) and the optional LAxisCtrl / CamExt technology libraries.

Migration Target: S7-1500 Technology CPU

The hardware successor for SIMOTION D is the SIMATIC S7-1500 TF / T-CPU combined with SINAMICS drives. The recommended mapping is:

For path interpolation and complex kinematics, S7-1500T/TF CPUs support the SIMATIC Motion Control library, which provides _cam, _path, _kinematics function blocks. The TF (Technology Functions) variant enables kinematic transformations and robotics-style interpolation without needing a third-party controller.

Software Migration: SCOUT → TIA Portal

There is no automatic converter from a SCOUT project to a TIA Portal project. Migration is manual and is structured as five engineering tasks. The TIA Portal version must support the target S7-1500 firmware (V2.8 → V3.1 covers the full T-CPU lineup as of the 2024–2025 release cycle).

1. Hardware Re-Assignment

• Export the SCOUT hardware catalog and map each SIMOTION D station to an S7-1500 T-CPU with equivalent cycle time.
• Map drive telegram: Standard Telegram 1 → Telegram 1; Siemens Telegram 105 → Telegram 105 (PROFINET IRT remains valid).
• Re-route PROFINET topology; SIMOTION D used IRT with isochronous mode; S7-1500 T-CPU supports the same isochronous PROFINET IRT configuration in TIA Portal device configuration.

2. Axis and Drive Re-Commissioning

• Create TO_Axis, TO_SynchronousAxis, TO_Cam, TO_CamTrack, TO_LeadingAxis proxies in the TIA Portal technology object tree.
• Re-enter mechanical data (load gear, spindle pitch, lead screw pitch, position limits) in the axis configuration.
• Re-enter the SINAMICS drive parameter set (P2900 family, motor ID, encoder interface, DSC — Dynamic Servo Control) via Startdrive.

3. Program Translation

• MCC charts: Translate to SCL/ST or to MCC-equivalent function blocks. The CAMTECH / Motion Tasks of SCOUT do not exist as TIA Portal native objects. The recommended equivalent is the LAxisCtrl technology library, which implements similar state machines for cam profile switching, fly-cutting, and gear engagement.
• ST / LAD / FBD units: These are conceptually compatible and can be re-keyed. Watch for SCOUT-specific system functions (e.g., _enableAxis, _homing) — replace with PLC Open blocks (MC_Power, MC_Home).
• Drive parameter access via DPV1 or DCC: Replace with Siemens drive telegrams or use the LAxisCtrl / DriveLib function blocks.

4. Cam and Synchronization

Camming in SCOUT was defined in the CAM editor and consumed by TO_Cam. In TIA Portal, cam disks are configured in the TO_Cam editor and interpolated via MC_CamIn / MC_CamIn. For electronic cam profile switching at runtime, use the LAxisCtrl library's cam-switching function blocks. Interpolating cams with leading-value-coupled gear changes are handled via TO_Cam_ext and the _cam_ext function blocks in the SIMATIC Motion Control library.

5. Commissioning and Verification

• Loop the S7-1500 T-CPU into TIA Portal online, verify axis TO configuration in Commissioning mode.
• Run the SCOUT-style test sequence: enable axis, jog, home, move absolute, run cam, run synchronization.
• Validate isochronous IRT by reading the PROFINET diagnostics — the IO device must report isochronous synchronization and RT-Class = RT / IRT.

Feature Gap Analysis: What You Lose

LAxisCtrl Library: Filling the Gap

The LAxisCtrl (Library Axis Control) is the Siemens-provided technology library that approximates the high-level axis-control and cam-management functions formerly native to SIMOTION. The library is published as a TIA Portal V15+ library package and is suitable for porting:

• Cam switching with on-the-fly profile change.
• Master-slave gear engagement/disengagement with controlled phase shift.
• Cross-coupled master (electronic line shaft replacement).
• Homing strategies (current-based, encoder-based, homing cam + zero pulse).
• Axis diagnostics, error reset, restart on the fly.

For functions not covered by LAxisCtrl (e.g., unique MCC chart semantics, vendor-specific motion tasks), engineering must build new SCL function blocks. Plan for 15–25% additional code in TIA Portal versus the original SCOUT implementation for equivalent feature parity.

Drive Telegram and Bus Configuration

For minimum configuration effort, retain the same Siemens drive telegram that was in the SCOUT project. The telegram type is set in the SINAMICS drive parameter P922 and the matching TIA Portal device configuration.

Engineering Impact: Sins of SIMATIC vs. Sins of SIMOTION

Migrated installations report an explicit trade-off: the T-CPU provides raw performance parity with late-model SIMOTION D, but engineers who relied on SCOUT's integrated MCC editor and Motion Tasks must now build state machines in SCL, S7-Graph, or external libraries. Common field observations:

• Free from SCOUT, but bound to TIA Portal: MCC charts and Motion Tasks are gone, but the project lifecycle, online diagnostics, and version control inside TIA Portal are stronger than SCOUT's isolated project model.
• Drive parameter access: SCOUT's drive parameter interface inside MCC is convenient; in TIA Portal, drive parameter reads/writes go through Startdrive or library FB readDriveParameter / writeDriveParameter.
• Cam management: SCOUT's TO_Cam editor and runtime cam switching are not 1:1 replicated; LAxisCtrl must be wired manually.

Spare Parts and Lifecycle Planning

For machines with 10+ years of in-service life, phase-out timing affects spare parts availability. Build a transition matrix per machine:

1. Identify the SIMOTION D variant and current firmware version in service.
2. Note the PM400 / PM410 milestone for that variant.
3. Order sufficient spare controllers to cover at least one failure event past the discontinuation date.
4. Schedule a migration to S7-1500 T-CPU for the next major retrofit.

Troubleshooting Migration Issues

Verification Checklist

1. Compare cycle time of original SIMOTION D application against target S7-1500 T-CPU OB91 servo cycle.
2. Run axis commissioning mode in TIA Portal; verify enable, jog, home, and position-absolute moves.
3. Export cam profiles from SCOUT, import to TIA Portal TO_Cam, verify against original points.
4. Run synchronization sequence (gear in, cam in, decoupling) on a test bench.
5. Validate PROFINET IRT diagnostics: rt-class = IRT, sync-state = locked.
6. Validate fail-safe response: simulate ESTOP, verify axis STO and S7-1500F stop category.
7. Document drive parameter changes for service (motor ID, encoder, telegram, P2900 family).

Frequently Asked Questions