Resolving the SINAMICS G130 CU320-2DP "Different Instance ID" Warning in STARTER

The Different Instance ID warning is one of the most persistent commissioning annoyances reported by engineers who integrate a SINAMICS G130 chassis drive equipped with a CU320-2DP Control Unit into a SIMATIC S7 project via Drive ES. The drive runs normally and parameters can be uploaded and downloaded from a PG that is connected point-to-point over Ethernet or PROFIBUS, yet the moment the drive is opened from the STEP 7 / HW Config right-click "Open with STARTER" shortcut, two warnings appear next to the drive object, the tree entry shows a red plug icon, and the parameter set is not synchronised back to the offline project.

This reference explains the root cause of the warning, what it actually means for the parameter data, the diagnostic steps that confirm a project mismatch, the three recovery workflows used in the field, and the engineering practices that prevent the warning from re-appearing on multi-engineer, multi-site projects.

1. Problem Description

Engineers typically encounter the warning under one of the following scenarios:

• Drive is commissioned on the shop floor with a stand-alone PG running STARTER (no STEP 7 / Drive ES integration). The PG is later connected to an S7-300 / S7-400 controller that owns the drive as a PROFIBUS slave. When the drive is opened through the SIMATIC project, the offline and online trees show a red plug icon next to the SINAMICS G130 and two warnings list "Different Instance ID" or "Topological difference / Project identifier does not match".
• Drive was originally commissioned with one version of STARTER (e.g. STARTER V5.4 SP3) and the project is later opened with another version (STARTER V5.5 / V5.6) that regenerates the project identifier even though the parameter values are identical.
• The project has been migrated between STEP 7 V5.x projects and TIA Portal projects, or copied from one station to another, so the embedded object identifier no longer matches the one stored in the drive's non-volatile memory (CompactFlash card on the CU320-2DP).
• Multiple engineers are working on the same drive from different PG images. The most recently connected PG uploads its identifier, and the next engineer to connect sees the mismatch.

The visible symptoms in STARTER are:

• Two warning entries in the information pane of the affected drive object ("Different Instance ID" on the drive object and on the connected Control Unit).
• A red plug icon on the drive object node, indicating that the offline parameter set is not in sync with the online drive.
• Load to PG / Load to target device actions either refuse to execute or appear to complete without writing any data to the offline project.
• No hardware fault, no F-fault, no A-alarm on the drive itself — the warning is a project-management warning, not a drive fault.

2. Root Cause Analysis

The SINAMICS drive platform stores a project identifier in two locations:

1. Offline project — written into the STARTER project file (.sdf, .sdp, or the embedded TIA Portal project). The identifier is generated by STARTER when the drive is first inserted into the project tree and is unique to the offline workstation, the project name, and the drive object name.
2. Online drive — written into the CU320-2DP's non-volatile memory (CompactFlash card, file /siemens/sinamics/.../proj.bin) when a "Download" or "Load to target device" is performed. The identifier is a 16-byte UUID plus a timestamp.

When STARTER connects online, it compares the offline and online identifiers. If they differ, it raises the Different Instance ID warning and refuses to mark the online and offline copies as consistent. The drive itself does not raise a fault because the identifier is purely a project-management object — it has no influence on closed-loop control, on the PROFIBUS / PROFINET slave interface, or on the drive's I/O mapping.

The mismatch can be introduced by any of the following actions, all of which are extremely common in normal project life:

The internal identifier is not exposed as a parameter in the SINAMICS parameter list. There is no r-parameter that the user can read to see the current identifier, and there is no p-parameter that the user can write to change it. The only way to manage the identifier is through the STARTER / Drive ES / TIA Portal project management layer.

3. Affected Components, Firmware and Software

The warning is independent of the SINAMICS firmware version on the CU320-2DP and independent of the power unit firmware on the Line Module, Motor Module or Active Line Module. Upgrading SINAMICS firmware (e.g. from V4.7 to V5.2 SP3) does not clear the warning — the identifier is written and read by STARTER, not by the drive firmware itself.

4. Diagnostic Procedure

Before applying a recovery workflow, confirm that the issue is in fact a project-identifier mismatch and not a real drive fault.

1. Connect the PG to the drive with point-to-point Ethernet (or PROFIBUS directly on CU320-2DP). Open STARTER as a stand-alone tool, not through HW Config.
2. Right-click the drive object and select Connect to target system → Online.
3. Observe the drive's information pane. If you see only F-codes and A-codes from the drive firmware, the drive itself is healthy. Any "Different Instance ID" warning shown in this stand-alone session is the same warning you will see in the integrated S7 project; if it is absent, the issue is not the identifier but the S7/STARTER integration path.
4. Check the drive's diagnostic buffer (parameter r0947[0...63]) and the alarm history (parameter r0947 and the AOP30 alarm list). A genuine drive fault would be listed here; the instance-id warning does not appear in the drive buffer.
5. Open the S7 project in STEP 7 / HW Config, right-click the SINAMICS G130, and choose Open with STARTER. Count the warnings in STARTER's information pane — typically two: one on the Control Unit (CU320-2DP) and one on the drive object (the inverter DO).
6. Right-click the drive and select Target system → Load to PG. If the action completes with a green checkmark, the parameter values are present in the offline project. The red plug icon may remain until the identifiers are reconciled — see Section 6.

5. What the Warning Actually Means for the Parameter Data

Engineers are rightly concerned that a warning on the drive object means the parameters were not uploaded. In practice, the warning refers only to the project identifier; the parameter values themselves are still transferred. Confirmation from a Siemens support specialist working with this exact scenario states that "the parameters are uploaded in full; the warning only refers to the internal identifier, so the values of the parameter upload contain all data."

Implications:

• A Load to PG action performed while the warning is active still produces a complete offline copy of all parameters (p0001 through the highest p-parameter, all BICO interconnections, the safety parameters of the SINAMICS Safety Integrated functions if present, and the free function blocks). The only thing missing is the equivalence of the project identifier.
• A Load to target device action performed from the offline project to the drive will overwrite the project identifier in the drive with the offline one, which clears the warning — but it also overwrites any parameters that were changed locally on the drive and not yet uploaded.
• Engineers who want a clean state must therefore decide whether the offline project or the online drive is the source of truth, and align both accordingly.

6. Resolution Workflows

Three workflows are commonly used. The right one depends on whether the offline project or the online drive is the source of truth.

6.1 Workflow A — Offline project is the source of truth

Use when the S7 project is documented, version-controlled, and the drive's parameters should be reset to the engineered values.

1. Open the S7 project in STEP 7.
2. Open the SINAMICS G130 with Open with STARTER.
3. Right-click the drive and choose Target system → Load to target device.
4. In the dialog, tick After loading, copy RAM to ROM. This writes the project identifier and all parameters to the CompactFlash card.
5. Confirm the prompt that the online connection is exclusive. STARTER will overwrite the identifier on the drive with the offline one.
6. Close and reopen the online connection to verify that the warning is gone and the plug icon is green.

6.2 Workflow B — Online drive is the source of truth

Use when the drive has been running with parameters that are not in the S7 project (e.g. optimisation done by a commissioning engineer on the shop floor), and the S7 project is to be brought up to date.

1. Open STARTER as a stand-alone tool and connect to the drive over point-to-point Ethernet or PROFIBUS.
2. Right-click the drive object and choose Target system → Load to PG. Accept the warning that the identifier differs.
3. Save the project under a new name (so the original is preserved) and perform a Copy RAM to ROM on the drive (button on the AOP30 or the menu item in STARTER).
4. Close the stand-alone project. Open the S7 project in STEP 7, right-click the drive, and choose Open with STARTER.
5. In the integrated STARTER, choose Target system → Load to PG again. The identifiers now match because the offline project inherits the drive's identifier on first online connection.
6. Save the integrated project. The warning will be gone for any subsequent engineer who opens the project.

6.3 Workflow C — Create a fresh offline project

Use when neither the S7 project nor the drive can be trusted, and a clean baseline is needed.

1. In STEP 7 HW Config, delete the SINAMICS G130 from the PROFIBUS / PROFINET topology.
2. Re-insert the SINAMICS G130 from the hardware catalogue, using the same order number (e.g. 6SL3310-1GE36-1AA3 for a typical 200 kW chassis unit) and the same PROFIBUS / PROFINET address.
3. Open the drive with Open with STARTER. STARTER will create a new DO with a new identifier.
4. Connect online, accept the warning, and perform Load to PG. The offline project now inherits the drive's identifier and the warning will be gone for all subsequent sessions.
5. Save the S7 project and perform a documentation archive of the project with STEP 7 → Archive so that the identifier is preserved across project handovers.

7. Verification

After running any of the workflows above, verify that the warning is gone and the offline and online copies are consistent.

1. In STARTER's online view, the plug icon on the drive object must be green. The icon states are: green plug = online and consistent; yellow plug = online and inconsistent; red plug = offline only or online with project-identifier mismatch.
2. STARTER's information pane must not list the "Different Instance ID" warning. There may still be other information-level messages (drive type, firmware version, PROFIBUS slave address) — these are not warnings.
3. Compare a sample of parameters between the offline project and the drive:
   • Drive commissioning parameters: p0010 = 0 (drive ready), p0002 = 0 (drive macro), p0100 = 0 (Europe, 50 Hz), p0205 = 1 (power unit application: variable torque).
   • Motor parameters: p0304 (motor rated voltage), p0305 (motor rated current), p0307 (motor rated power), p0311 (motor rated speed), p0314 (motor pole pair number).
   • Control parameters: p1120 and p1121 (ramp-up and ramp-down times), p1300 = 20 (open-loop speed control) or p1300 = 21 (closed-loop speed control).
4. Save the S7 project, close it, and re-open it. The warning should not return. If it does, the identifier was not committed to non-volatile memory — repeat the workflow with "After loading, copy RAM to ROM" ticked.
5. From a second PG, open the same S7 project and connect online. The warning should also not appear on the second PG, which confirms that the identifier is in the offline project file and not just in the first PG's local copy.

8. Integration with SIMATIC S7 Projects (Drive ES / Startdrive)

The interaction between the S7 project and the drive is mediated by the Drive ES / Startdrive software, which embeds a STARTER project in the S7 project. When the drive is opened from HW Config, STARTER is launched with the embedded project. The identifier of the embedded STARTER project is what is compared with the identifier on the drive.

Common project-management pitfalls that re-introduce the warning even after a clean recovery:

• "Reorganise" or "Save as" with a new name — STARTER / STEP 7 may regenerate the identifier. Always use the same project name across handovers.
• Copying the S7 project via Windows Explorer — this preserves the embedded STARTER project but may add a workstation tag that STARTER treats as a different identifier. Use STEP 7's Archive / Retrieve to move projects between stations.
• Migrating from STEP 7 V5.x to TIA Portal — the Startdrive import wizard regenerates the identifier. After migration, perform Workflow A or B once, with "Copy RAM to ROM" ticked.
• Multiple S7 stations sharing one drive — when the same drive is referenced from more than one S7 station (e.g. a hot-standby PLC pair), only the station that most recently downloaded will match the drive identifier. The other station will show the warning until it is brought online and a "Load to PG" is performed.

9. Relationship to Genuine Drive Faults

The Different Instance ID warning has no relationship to drive-side F-codes and A-codes. The complete list of drive-side faults and alarms for the SINAMICS S/G platform (including the G130) is published by Siemens in the "Drive Error Messages" technology template for SIMATIC CPU31xT. The template documents how a SIMATIC CPU can monitor a SINAMICS S/G drive's alarm buffer via standard S7 communication and forward genuine drive faults (F-codes such as F30002, F30003, F07900) and alarms (A-codes) to the operator. None of these faults are triggered by a project-identifier mismatch; the instance ID warning is a STARTER-side condition and must be treated separately.

When the red plug icon is on the drive object, the drive itself is normally running. Operators and maintenance engineers should be trained to look at the drive's actual fault and alarm indicators (the AOP30, the drive's LED, the starter alarm pane) rather than the plug icon in STARTER to determine the drive's health.

10. Preventing Future Instance ID Mismatches

1. Define a single source of truth for the project. If the S7 project is canonical, lock down the drive so that local changes require a deliberate "Load to PG" action.
2. Use STEP 7's Archive function (not Windows copy) to move the S7 project between engineers. Archiving preserves the embedded STARTER project and its identifier exactly.
3. After every change to a drive, perform Load to target device with Copy RAM to ROM ticked. The CF card on the CU320-2DP must hold the same identifier as the offline project; otherwise the next engineer to connect will see the warning.
4. Maintain a single engineering workstation image (or a small set of identical images) for the project. Mixed images with different STARTER versions are the most common cause of the warning re-appearing on a previously clean project.
5. When replacing the CU320-2DP or its CompactFlash card, treat the new unit as having no identifier. Run Workflow B (load from drive to PG) after the first online connection so the offline project inherits the new identifier.
6. For multi-site plants, version-control the S7 project (e.g. with Siemens Automation License Manager + project versioning, or with an external version-control system for the archived .s7p file). Each committed version should include a note that the drive identifier was last reconciled on a specific date.
7. For plants using the AOP30 as the operator panel, be aware that the AOP30 cannot change the project identifier. The identifier can only be managed through STARTER or Drive ES / Startdrive.

11. Cross-Reference: Comparable Behaviour in Other SINAMICS Drive Families

The same warning appears across the SINAMICS family wherever a CU320-2DP or CU320-2PN is used, including the SINAMICS S120, S150, G150 and G130. The cause and the recovery workflows are identical. On SINAMICS S120, where multiple drive objects can be configured in one CU (e.g. an infeed plus two motor modules), the warning may appear on individual DOs rather than on the CU; this is normal and is resolved by the same workflows. On SINAMICS G120 with a CU230P-2 or CU240E-2, the warning is reported as "Project assignment does not match the target system" and is resolved the same way; the firmware tool on those drives is IOP/BOP plus the SINAMICS Startdrive or STARTER PC tool.

SINAMICS V90 and V20 drives use a different identifier concept and the warning does not appear.

12. Frequently Asked Questions