SINAMICS G120C PROFINET Recovery: Restoring Station Name and IP After MMC-to-Drive Copy

Field-proven diagnostic and recovery procedure for SINAMICS G120C frequency inverters that report "No Cyclic Connection" (F08501) with blinking BF LEDs on both the drive and the SIMATIC CPU 315-2 PN/DP after a memory card parameter copy. Covers parameter inspection (r61000, r61001), MMC dataset and .ini-file verification, PROFINET name re-assignment, RAM-to-ROM persistence, safety re-acceptance, and operator-friendly "idiot-proofing" of the swap-out workflow.

1. Problem Description and Field Context

On a shipboard conveyor plant, two SINAMICS G120C inverters (2.2 kW rated) equipped with the Intelligent Operator Panel (IOP) and a SINAMICS Micro Memory Card (MMC) communicate with a SIMATIC S7-300 CPU 315-2 PN/DP over PROFINET. Standard telegram 352 is the cyclic data exchange, configured in TIA Portal V13 SP1 Update 9 with Startdrive V13 SP1 Update 3. Each drive is connected to the PROFINET network with a unique station name and a fixed IP address inside the project's automation subnet.

After a routine maintenance intervention in which the technical crew believed one of the drives to be at fault, the following operations were executed on both inverters:

1. A factory reset (suspected by the engineering team, not confirmed by the crew).
2. A "Memory card to drive" copy of the parameters from the SINAMICS MMC back into the G120C.

After the copy, both drives became unreachable. The PLC CPU 315-2 PN/DP and the G120C units show a blinking Bus Fault (BF) LED, and the drive diagnostic buffer contains the F08501 "No Cyclic Connection" fault. PROFINET cyclic communication is interrupted on both inverters simultaneously. The PLC remains reachable for online diagnostics through a separate engineering path, indicating the controller itself is healthy and the PROFINET cable plant is not at fault. The most likely root cause is that the PROFINET station name and IP identity were not restored from the MMC .ini-file, either because the file was not regenerated with the ProfinetName key after the last parameter change, or because a factory reset cleared the volatile name and the subsequent MMC restore did not write it back.

2. System Topology and Reference Configuration

The reference installation consists of the following components. Use this as a checklist when validating any new build that exhibits the same symptoms.

The PROFINET network is the standard S7-300 PROFINET IO topology, where the CPU 315-2 PN/DP acts as the IO controller and each G120C is an IO device. The IO controller assigns the IP address to the IO device at the moment the IO device identifies itself on the bus with the correct PROFINET station name. The IO controller pulls the IP, subnet mask, and gateway from the device configuration in TIA Portal and pushes it via DCP (Discovery and Configuration Protocol) to the named device.

If the IO device has no station name, the DCP identification request is rejected by name, and the controller cannot resolve the device to assign the IP. This is the most common root cause for a F08501 "No Cyclic Connection" fault on a freshly restored G120C that has its parameters back but lost its PROFINET identity.

3. Symptoms and Diagnostic Indicators

The failure pattern is consistent and reproducible. Each item below should be confirmed during the diagnostic phase before any recovery action is taken.

3.1 LED State on the G120C

• BUS LED (PROFINET) red, blinking with a regular 2 Hz cadence: PROFINET bus fault, no configuration matched or no physical link partner present.
• RDY LED green, possibly intermittent or flashing slowly: drive is in "ready to run" state but communication is not established.
• If the BF LED is OFF and a different fault is shown on the IOP, the issue is not PROFINET identification but a parameter mismatch; consult the SINAMICS G120C fault list.

3.2 LED State on the CPU 315-2 PN/DP

• BF LED blinking: at least one configured PROFINET IO device is in station failure or is not reachable.
• MAINT LED may be ON if the device is configured but the configured and actual topology differ.
• Diagnostic buffer entry: "Station failure" on the affected PROFINET IO device slot.

3.3 Drive Fault Code

Open the IOP or use the engineering tool to read the active fault. The expected entry is:

• F08501 - "PROFINET: No cyclic connection" (CU parameter r0947[0] / r2122).
• Fault value (r0949[0]) typically points to a missing or mismatching telegram; 352 in this case.

3.4 Parameter Inspection

Two read-only parameters are the primary diagnostic source on the G120C for PROFINET identification state:

When r61000 shows only numeric characters or is empty, and r61001 shows 0.0.0.0, the drive has not been commissioned for PROFINET IO. The PLC cannot find it and the BF LED is the visible consequence.

4. Root Cause Analysis: Why the Station Name Is Lost After an MMC Restore

There are three independent mechanisms that can leave a G120C without a PROFINET station name after a memory card to drive copy. Each is examined below. In field service, the most common cause is the combination of (1) and (2): the .ini-file is not generated for dataset 0, or it is generated but without the PROFINET name field filled in.

4.1 The .ini-File Is Not Created on the MMC

The PROFINET communication parameters (station name, IP, subnet, gateway, telegram selection) are not stored in the standard parameter set p0010 = 0. They live in a separate initialization file on the MMC, conventionally located in:

For a G120C, the standard communication parameter storage is dataset 0. The .ini-file is created when a "RAM to ROM" save is performed with the communication parameters present. If the user performs only a "Save drive to memory card" without a "RAM to ROM" first, the .ini-file is not always updated with the latest PROFINET settings, depending on the firmware version.

4.2 The .ini-File Is Created but the PROFINET Name Field Is Empty

Observed on a TIA V13 SP1 / Startdrive V13 SP1 / G120C firmware V4.7 SP3 stack: the .ini-file is generated and copied to the drive, but the [Communication] section is missing the ProfinetName key, or ProfinetName is empty. The result is the same as 4.1: the drive comes back with default name and 0.0.0.0.

Root cause candidates:

1. The PROFINET name was assigned in TIA Portal but "Download to device" was not performed against the drive (only the PLC project was downloaded). The name lives in the drive's volatile NVRAM (r61000) but is not in the parameter backup set.
2. The user performed a "Factory reset" on the drive before the MMC restore. The factory reset wipes r61000.
3. The .ini-file on the MMC was generated with a previous firmware version that did not include the ProfinetName key, and the file is not regenerated after a parameter change.

4.3 PROFINET Stack Does Not Persist the Name Across Power-Cycle

On early G120C firmware versions, the PROFINET name was stored in volatile memory and only persisted when the drive was put into "save" mode through the IOP. After a power cycle, the name was lost again. From firmware V4.7 onwards, the name persists automatically when present in the .ini-file. Verify the firmware on the affected drive:

1. IOP: Diagnostics → Version → Control Unit firmware.
2. Parameter r0018 / r0964[0] / r0975[0] (depending on firmware): Control Unit firmware version.
3. Web server (if enabled): "Drive Identification" page.

5. Step-by-Step Diagnostic Procedure

1. Confirm the BF LED pattern on the G120C and the CPU.
2. Read the active fault on the drive using the IOP or Startdrive. Confirm F08501 "No cyclic connection".
3. Read r61000 and r61001 on the drive. If r61000 is empty or numeric-only, the station name is missing. If r61001 is 0.0.0.0, the IP has not been assigned.
4. Power down the drive. Remove the SINAMICS MMC and insert it into a card reader connected to a PC running SINAMICS Startdrive or a generic text editor.
5. Navigate to /user/sinamics/data/. Locate the *.ini file corresponding to dataset 0 (typically 00.ini or named after the dataset index).
6. Open the .ini-file in a text editor. Look for a [Communication] section. Verify the presence of:
   • ProfinetName=<name>
   • IpAddress=<oct1.oct2.oct3.oct4>
   • SubnetMask=<mask>
   • DefaultGateway=<gw>
7. If the .ini-file is missing or the [Communication] section is incomplete, note it and proceed to section 6 (recovery).
8. If the .ini-file is present and complete, the issue is most likely a firmware version mismatch. Check the drive firmware against the project firmware version in TIA Portal.
9. Cross-check the PROFINET device name configured in TIA Portal under "Devices & Networks → PROFINET interface → PROFINET device name". The string must be byte-for-byte identical to the ProfinetName in the .ini-file.
10. Inspect the PLC diagnostic buffer for the station failure entry. Confirm the configured device name matches the one in TIA Portal.

6. Recovery Procedure: Restoring PROFINET Communication

Three independent recovery paths are available. Use path A first; if it fails, use path B; if both fail, escalate to path C.

6.1 Path A - Assign PROFINET Station Name from TIA Portal

1. In TIA Portal, open the project for the affected plant.
2. Right-click the affected G120C device in the network view. Select "Assign PROFINET device name".
3. In the dialog, enter the exact PROFINET device name configured for this device. Select the G120C's PROFINET MAC address (printed on the drive label, format 00:0E:8C:xx:xx:xx or 28:63:36:xx:xx:xx depending on hardware revision). Click "Assign name".
4. Wait for the dialog to confirm the assignment.
5. Power-cycle the drive. The CPU will detect the named device on the bus and push the configured IP via DCP. r61001 will show the assigned IP and the BF LED on both the drive and the CPU will go OFF.
6. Verify the cyclic communication is back: on the PLC, the station should report "OK" in the online diagnostics; on the drive, F08501 should clear automatically.

6.2 Path B - Regenerate the .ini-File on the MMC

If path A re-establishes the communication but the operator wants the swap-out process to be repeatable without a TIA Portal, regenerate the .ini-file:

1. Use a fresh or wiped MMC card. The old card can be reformatted (FAT32) and reused, but back up any data first.
2. Insert the MMC into the drive while the drive is powered down.
3. Power up the drive. Communication is now active (assigned in step 6.1).
4. On the IOP, navigate to "Settings → Save data to memory card" or "RAM to ROM". This forces a write of the current parameter set and the .ini-file to the MMC.
5. Alternatively, in TIA Portal, use Startdrive to perform "Upload from drive → RAM to ROM" and "Copy RAM to ROM".
6. Power down the drive. Remove the MMC. Verify on a PC that /user/sinamics/data/00.ini now contains the complete [Communication] section with the ProfinetName key.
7. Reinsert the MMC and power up. The drive should now self-configure its PROFINET identity from the MMC at boot.

6.3 Path C - Use PRONETA for Out-of-Project Recovery

When the TIA Portal project is not available on site, use the Siemens PRONETA tool to assign the station name directly to the drive:

1. Connect a PC with PRONETA to the PROFINET network. PRONETA is available free of charge from Siemens Support.
2. Perform a network analysis. PRONETA will list all reachable PROFINET devices including unconfigured ones (no station name, 0.0.0.0).
3. Identify the affected G120C by its MAC address or device type.
4. Use the "IO Test" or "Network Analysis → Station" function to assign the station name and IP. The name and IP must match the project configuration; if no project is available, a temporary name can be assigned to verify the link.
5. Once the name is assigned, the IO controller (the CPU) will detect the device and complete the configuration handshake.

7. Telegram 352 - Standard Configuration Reference

Standard telegram 352 is the Siemens default for SINAMICS G120/G120C/G120D/G120P drives in standard (non-safety) applications. It is a 6-word input / 6-word output PZD mapping, sufficient for the typical control word (STW1), setpoint speed, status word (ZSW1), and actual speed feedback used in a conveyor application.

Verify that p0922 = 352 on the affected drive. If p0922 is set to 0 (no telegram) or to a value that does not match the project, the drive will raise F08501 even with a valid station name and IP. Cross-check p2040 (PROFINET monitoring time) against the configured PROFINET update time in the controller; a too-short monitoring time will cause spurious station failures during PLC stop-ramp-up transitions.

8. SINAMICS MMC: Dataset Structure and Persistence Model

The SINAMICS MMC stores three independent data sets on a single card. Understanding this structure is essential for predictable swap-out behavior.

Rules of thumb:

• The PROFINET .ini-file is generated only for dataset 0. Datasets 1 and 2 do not include the PROFINET identity in their .ini-file by default.
• A "Save drive to memory card" (p0971 = 1) writes the current parameter set to dataset 0 and creates a fresh .ini-file.
• A "Memory card to drive" (p0802 = 1) reads dataset 0 from the MMC and writes it to the drive RAM, then triggers a RAM-to-ROM save on the drive.
• A "Factory reset" (p0970 = 1) wipes the drive parameters back to defaults. PROFINET name is cleared. A subsequent "Memory card to drive" with a valid dataset 0 on the MMC restores parameters but not the PROFINET name if the .ini-file lacks the ProfinetName key.
• On firmware V4.7 SP3+, datasets 1 and 2 can be configured to include PROFINET identity, but only with a SINAMICS engineering tool and an explicit "RAM to ROM" save on the working drive.

9. "Idiot-Proofing" the Swap-Out Process

Field service technicians, especially onboard a ship with rotating crews, benefit from a clearly documented and validated swap-out procedure. The following checklist makes the recovery process repeatable with no engineering tool.

9.1 Pre-Deployment MMC Preparation

1. With the drive in its final commissioned state, perform "RAM to ROM" on the IOP or in TIA Portal.
2. Perform "Save drive to memory card". Verify on a PC that the .ini-file contains the ProfinetName key.
3. Label the MMC with the drive order number, station name, IP address, and firmware version. Use a small label printer (e.g. Brady BMP21) for legibility.
4. Store the MMC in a sealed ESD bag attached to the drive enclosure with a cable tie.

9.2 Operator Swap-Out Procedure

1. Power down the drive. Swap the MMC from the failed drive to the spare drive (or the same drive if it is recovering).
2. Power up. The drive reads dataset 0 from the MMC and applies the parameters and the .ini-file.
3. Wait 30 seconds. The drive should reach "ready" and the BF LED should be OFF.
4. If the BF LED is ON or blinking, the .ini-file did not include the PROFINET name. Use a laptop with PRONETA (or a backup USB-to-PROFINET adapter) to assign the station name. The crew on board should be trained for this step.

9.3 Spare-Drive Strategy

Keep a pre-commissioned spare drive per critical conveyor. The spare drive should be programmed with the same MMC and stored in the same cabinet. The crew pulls the failed drive, installs the spare, and the line is back up in 10 minutes. Re-program a new spare on the next port call.

9.4 Why S7-300 CPUs Self-Recover but G120C Does Not

The S7-300 CPU 315-2 PN/DP uses the MMC as its primary boot medium, and the PROFINET device name, IP, and project data are stored in the CPU's load memory on the card. When a CPU is replaced, the new unit boots from the card with the original identity fully restored. The SINAMICS G120C stores the PROFINET identity in a separate .ini-file on the same physical card, and that file is only generated when a "RAM to ROM" save is performed with the communication parameters present. If the user has never explicitly saved a .ini-file with the ProfinetName key, the card will not restore the PROFINET identity automatically, even though the parameter set is restored correctly.

10. Safety-Related Considerations

If the SINAMICS G120C is part of a safety-integrated application (Safety Integrated via PROFIsafe, Extended Functions, or Basic Functions), the parameter copy alone is not sufficient to re-establish operation. After a memory card restore, the safety functions must be re-accepted and the safety password re-entered.

Verification steps after a memory card copy on a safety-integrated drive:

1. Check r9771 (SI Common diagnostics). Look for the "safety parameters changed" and "SI acceptance test required" bits.
2. Check r9871 / r9793 (depending on firmware) for the safety checksum validity. A mismatch indicates the safety parameters have been modified but not yet accepted.
3. If the acceptance test is required, perform it through the IOP or Startdrive. Document the test results.
4. Confirm the safety telegram (typically PROFIsafe telegram 30) is configured in p0922 alongside the standard telegram 352, or use the safety-aware variant telegram 352 + 30.

If the drive was ordered without Safety Integrated firmware enabled, the safety parameters are not present and the acceptance test is not required. The G120C order number suffix (e.g. ...-1KE1x-...) determines whether the safety option is loaded. Drives ending in -1KE15 typically carry the safety option, while -1KE13 do not. Verify against the order documentation before assuming safety is in scope.

11. Verification and Commissioning Checklist

After completing the recovery, run the following verification sequence. Each step must pass before the drive is returned to service.

12. Troubleshooting Matrix

13. Firmware and Version Compatibility

Confirm the firmware of the SINAMICS G120C before any parameter copy or restore. Mixing parameter sets between firmware versions can corrupt the safety checksum and force an acceptance test. Recommended baseline for the configuration described in this article:

• SINAMICS G120C Control Unit firmware: V4.7 SP3 or later (V4.7 SP6 recommended for current Startdrive V13 SP1 support).
• SINAMICS IOP firmware: V1.6 or later, matching the Control Unit family.
• Startdrive: V13 SP1 Update 9 (the last Startdrive V13 maintenance update; later Startdrive versions require TIA Portal V14 SP1 or later).
• TIA Portal: V13 SP1 Update 9 (paired with Startdrive V13 SP1 Update 9).
• CPU 315-2 PN/DP firmware: V3.2.6 or later for PROFINET IO conformance class C.

When upgrading firmware on a drive that has been in service for more than two years, run the SINAMICS firmware update tool with the "Accept all parameters" option, then perform a manual acceptance test on the safety functions. Reset the IOP to factory default after the firmware update to clear any display-side cached parameter values.

14. PROFINET Name Rules and DCP Behavior

The PROFINET device name is a string of 1 to 240 characters, conventionally restricted to the labels allowed by the DNS-like rules used by DCP. Common conventions in plant engineering:

• Lower-case letters, digits, and hyphens only.
• Must not start or end with a hyphen.
• Uniqueness within the PROFINET network is enforced by the controller during the name assignment step.

For conveyor drives in the reference plant, a typical naming scheme is cnv1-drv-a for conveyor 1 drive A, cnv1-drv-b for conveyor 1 drive B, and so on. The IP is typically assigned in a dedicated range, e.g. 192.168.1.10 / 24 for IO devices and 192.168.1.1 for the CPU 315-2 PN/DP. Match the project configuration in TIA Portal and verify the gateway points to the correct router when the drive is reachable from outside the IO subnet.

15. Engineering Documentation Reference

The following Siemens official documentation supports the procedure described above. Always consult the most current edition of each document for the firmware version in use.

• SINAMICS G120C Operating Instructions - Commissioning, MMC handling, parameter list.
• SINAMICS G120C List Manual - Complete parameter list, including r61000 and r61001.
• PROFINET Field Devices Integration into TIA Portal - PROFINET device name assignment, topology, DCP.
• SIMATIC S7-300 CPU 31xC and CPU 31x Manual - CPU 315-2 PN/DP PROFINET IO controller setup.
• SINAMICS Startdrive Commissioning Manual - Startdrive V13 SP1 / V14 commissioning flows.
• SIMATIC PROFINET with S7-300/400 System Manual - PROFINET IO data exchange, telegram configuration.
• SINAMICS Safety Integrated Function Manual - Acceptance test procedure for safety-integrated drives.
• PRONETA Tool User Manual - Network analysis and station name assignment without TIA Portal.