SINAMICS G120 CU240E-2 DP-F Download Program from STARTER

Problem Overview: G120 Drive Replacement and Program Recovery

Replacing a SINAMICS G120 Control Unit in the field is a routine service operation, but it is also a common source of commissioning errors. The classic scenario is a failed CU240E-2 DP-F Control Unit where the technician can read the project off the defective drive, swap the Control Unit and/or Power Module for a spare, and then cannot push the recovered parameter set back to the replacement hardware. STARTER 5.4 displays the new drive in Accessible Nodes over the PROFIBUS point-to-point link, the connection is live, yet Download to Target Device refuses to write the project.

Three independent root causes account for the vast majority of these failures:

1. The PROFIBUS node address stored in the offline project (p0918) does not match the address set on the new Control Unit's DIP switches or in its delivery-state p0918.
2. The firmware version on the spare Control Unit does not match the firmware version embedded in the STARTER project (V4.7, V4.7 SP13, V5.1, V5.2 SP1, etc.). STARTER will not write a V4.7 project to a V5.2 device without an explicit firmware upgrade or downgrade step.
3. When the Power Module is replaced as well, STARTER detects a power-stack mismatch (different PM order number, rated current, or internal topology) and blocks the download until the Power Module identification is accepted or manually corrected.

All three are diagnostic-friendly once you know where STARTER reports the error. This reference walks through the correct upload, modify, and download sequence, and gives a troubleshooting matrix for every common failure mode when commissioning a spare G120 on a machine still maintained from SIMATIC Manager / STARTER 5.4.

System Prerequisites and Tooling

For safety-integrated projects on the CU240E-2 DP-F, also confirm that you have the Safety password (the password for the Safety Integrated configuration) on hand. The default delivery password on a brand-new unit is 0; the password on the old unit must be reused or the safety parameters will not be accepted on download.

SINAMICS G120 Modular Architecture You Must Understand

The SINAMICS G120 is a two-part drive: a Control Unit (CU) that handles communication, closed-loop control, I/O, and Safety, and a Power Module (PM) that handles the IGBT stack and DC link. Both have their own firmware and their own order number. When you swap a unit in the field you must know which of the four combinations you are dealing with:

• CU replaced, PM same - the new CU must be set to the same PROFIBUS address, the firmware must match, and the drive must learn the PM ID.
• CU same, PM replaced - rare; the CU must accept a new power-stack ID (parameters r0200 / p0200).
• CU replaced, PM replaced - the most common service case; both firmware and PM-ID mismatches are likely.
• Neither replaced - only firmware update - covered in the STARTER help under Online > Target Device > Firmware Update.

The CU240E-2 DP-F (order number 6SL3244-0BB13-1PA0 or -1FA0 depending on variant) supports PROFIBUS DP-V0/V1 and Safety Integrated (STO, SS1, SLS, SSM). The PROFIBUS address is set in two ways:

1. Via the address DIP switches on the front of the CU (switches 1 to 7, binary-weighted, valid range 1-126). Switch position 0 = 0 means p0918 is used.
2. Via parameter p0918 (CU address) - written by STARTER or HMI, only active when DIP switches are all OFF.

Step 1 - Upload the Existing Program from the Failing Drive

1. Open STARTER 5.4 and create an empty project, or open the existing machine project.
2. Connect the PG to the 9-pin PROFIBUS socket on the failing CU240E-2 DP-F using a USB-to-RS485 PC adapter (PC adapter USB A2, order 6GK1 571-2AA00) or a SIMATIC PG with native PROFIBUS.
3. Set the PG/PC interface in the Windows Control Panel Set PG/PC Interface to S7ONLINE (STEP7) > PC Adapter (PROFIBUS) or PC internal > ... > TCP/IP-Auto depending on your cable.
4. In STARTER click Online > Accessible Nodes. Confirm the drive appears with its actual PROFIBUS address and that the firmware version reads back correctly (for example, V4.7 SP13).
5. Right-click the drive in the project tree and choose Target Device > Upload to PG/PC (or Load to PG/PC depending on STARTER version). This reads every parameter, the Safety configuration, the PROFIBUS configuration, and the drive topology into the offline project.
6. Right-click the drive and choose Copy RAM to ROM on the live drive first - then archive the offline project with Project > Archive. Save the archive to a network share and to a USB stick.

Step 2 - Match the New Drive to the Project Before Download

Before you connect to the spare drive, prepare the offline project so the download will be accepted the first time.

1. In the project tree, open Drive > Configuration > Drive > Overview and verify the firmware version shown under Device identification. Confirm it matches the firmware on the spare CU (visible on the unit's sticker or under Accessible Nodes).
2. If the firmware versions do not match, do one of the following:
   • Use Online > Target Device > Firmware Update to push the correct firmware to the spare CU before downloading the project. This requires the matching firmware file on the STARTER installation DVD (for example CU240E2_DP_F_V5_2_1.upd).
   • Or, in the offline project, right-click the drive and select Target Device > Device Version to change the project's firmware version to match the spare. Re-archive after this change.
3. Set the PROFIBUS address. Open the drive's Communication > PROFIBUS page and confirm p0918 matches the address you will set on the new CU's DIP switches (or the address already set in the spare's p0918 if you intend to keep it). If you intend to use the DIP switches, set them now - 0/0/0/0/0/0/0 means the parameter p0918 is active; any other pattern means the DIP switches are active and p0918 is read-only.
4. Open Drive > Configuration > Power Module and confirm the PM order number, rated power, and rated current match the Power Module that will be installed. If you are also replacing the PM, enter the new PM's data here.
5. For safety-integrated projects, open Functions > Safety Integrated > Configuration and confirm the Safety password is the one that the new CU will accept. The new CU's Safety password is 0 by default; if the old project used a different password, you must clear Safety Integrated on the new CU (or you will get a Safety parameter rejection on download).

Step 3 - Connect to the New Drive and Download

1. Power off the machine. Replace the failing CU240E-2 DP-F with the spare. Reconnect the PROFIBUS cable, the encoder, and the STO wiring (terminals 16, 17, 18 on the CU240E-2 DP-F).
2. Power on the Control Unit only (24 V on the CU) - the PM does not need to be enabled for the download. The drive should come up in Ready to Switch On state (display: S or r 0000 on the BOP-2).
3. Connect the PG via PROFIBUS as in Step 1. Open Online > Accessible Nodes and confirm the new drive is visible at the expected address with the expected firmware.
4. In the project tree, right-click the new drive icon and choose Download to Target Device.
5. When prompted, select Download > After loading, copy RAM to ROM - this writes the project to the CU's non-volatile memory (CF card on the CU if fitted, or flash on the unit).
6. STARTER will display a comparison list (online vs. offline). Check the Safety Integrated lines carefully. If STARTER reports a Safety parameter mismatch, click Disable Safety in the dialog and acknowledge the prompt - the Safety parameters will be written in a second download after the standard parameters are in place.
7. After the download, perform a manual Copy RAM to ROM (right-click the drive in online mode > Target Device > Copy RAM to ROM). Without this step, the parameters are lost on the next power-off.

Root Cause 1 - PROFIBUS Address Mismatch

The single most common reason a G120 download fails after a Control Unit swap is a PROFIBUS address mismatch. STARTER will report one of the following messages:

• Target device could not be found at the configured PROFIBUS address
• Connection to the target device failed (error 0xE)
• Target device responded at address X, but the project is configured for address Y

Fix procedure:

1. Read the actual address from the drive front panel (BOP-2 menu, parameter r0918) or from the DIP switches.
2. Compare with the project's configured address (parameter p0918 in the offline project).
3. Choose one of the two to be the source of truth and change the other to match. The most reliable approach in the field is to set the DIP switches to the project's address - this is hardware-visible and survives any project change.
4. For a drive delivered with address 126, change the DIP switches to the machine's address before powering on the CU. The change is read on every power-up.

The address is not changed by downloading a new project - STARTER can read and display p0918, but the address is part of the PROFIBUS configuration and STARTER will refuse to write it while the bus is live if doing so would collide with another node. To change the address of a slave that is alone on a point-to-point link with the PG, use the BOP-2 (set p0918 = 3, for example) or use the Commissioning > Set Address wizard in STARTER.

Root Cause 2 - Firmware Version Mismatch

STARTER versions before V5.4 SP3 cannot open projects that target firmware V5.2 SP1, and STARTER V5.4 will not write a V5.2 SP1 project to a V4.7 SP13 device without an explicit firmware change. The error reported is The firmware version of the target device does not match the firmware version of the project.

To upgrade the spare's firmware from STARTER:

1. Open the project with the spare drive online.
2. Choose Online > Target Device > Firmware Update.
3. Select the firmware file matching the project (file extension .upd, located in the STARTER installation under D:\SINAMICS\FW\CU240E2_DP_F\V5_2_1\ or similar).
4. Tick Activate firmware after update and confirm.
5. The CU will reboot. After reboot, run Accessible Nodes again to confirm the new firmware version, then proceed with the project download.

Root Cause 3 - Power Module ID Mismatch

When the PM is replaced as well, the new Control Unit does not yet know the electrical characteristics of the new Power Module. STARTER reports Power module identification (r0200) does not match the configured value. The drive refuses to enable until the mismatch is acknowledged.

Resolution:

1. Open the drive in online mode.
2. Navigate to Drive > Configuration > Power Module.
3. Read the actual PM order number from r0200 - the new PM's data is detected automatically on the first run-up.
4. Click Accept actual topology or manually enter the new PM's order number (printed on the PM front label, format 6SL3210-1Pxxx-xxxx).
5. Save the project and re-download.

For PM240-2 Power Modules with the internal braking chopper, also confirm parameter p0219 (braking chopper configuration) is set to match the new PM - this is not always auto-detected.

Root Cause 4 - Safety Integrated Password and Parameters

On a CU240E-2 DP-F the Safety Integrated configuration is stored with a separate password hash. The default password on a new unit is 0. If the original project used a non-zero Safety password, STARTER will reject the Safety parameter block on download.

1. Open the online project and navigate to Functions > Safety Integrated > Configuration.
2. Click Change Settings; STARTER will prompt for the current Safety password of the target device, not the project.
3. Enter 0 (the default for a new unit) to unlock the Safety configuration.
4. Disable Safety Integrated in the target device with Functions > Safety Integrated > Disable. The drive cycles the Safety state machine to Safety parameters not yet configured.
5. Re-attempt the project download. The Safety block will be accepted because both the project and the device now use 0 as the working password.
6. Re-enter the original Safety password in the project (or in the device) to restore the production state.
7. Perform a Safety acceptance test per EN 61800-5-2 / EN ISO 13849-1 before returning the machine to production. This step is mandatory and not optional.

Root Cause 5 - Drive State, Commissioning Mode, or Fault Active

STARTER cannot write to a drive that is in a fault state, in commissioning mode with the motor spinning, or in a state that has parameters locked. The drive must be in Ready to Switch On (r0002 = 4) or Switched On (r0002 = 6), with no active fault (r0945 empty) and no active alarm that blocks commissioning.

• If the drive shows a fault code (for example F30002 DC link overvoltage, F07801 motor overcurrent, F1910 STO active), clear the fault with the acknowledge button (BOP-2 Fn) or with p3981 = 0 (acknowledge all faults).
• If p0010 (commissioning parameter filter) is not 0, STARTER downloads will be incomplete. Set p0010 = 0 in online mode, save to ROM, and retry.
• If the drive is in Safety commissioning mode (r9770 bit 0 = 1), exit with Functions > Safety Integrated > Exit Commissioning.

Verification After Download

1. In STARTER, open the project online. Navigate to Drive > Diagnostics > Status Word / Control Word and confirm the drive is in Ready to Switch On.
2. Open Drive > Configuration > Overview and verify the firmware, PM order number, and PROFIBUS address match the project's expected values.
3. Open Functions > Safety Integrated > Status and verify Safety parameters consistent (r9774 bit 0 = 1) and that the Safety password hash is the one expected.
4. Check r0945 (fault buffer) and r2122 (alarm buffer) for any new entries written during the download.
5. Perform a quick jog test from the BOP-2 (HAND mode, setpoint 5 %) to confirm the motor turns in the correct direction and at the correct speed.
6. Disconnect the PG. Power-cycle the drive (24 V off, wait 10 s, power on). Confirm the drive returns to Ready to Switch On and the parameters are still present - this proves the Copy RAM to ROM step worked.
7. Re-run the Safety acceptance test if Safety Integrated was touched.
8. Archive the final project with Project > Archive and save to the machine's documentation folder.

Troubleshooting Matrix

Migration to TIA Portal / Startdrive - Practical Note

Many service teams are migrating from SIMATIC Manager / STARTER 5.4 to TIA Portal with Startdrive while keeping older machines on the legacy tool. A project archived from STARTER (ZIP file) can be opened in TIA Portal with Startdrive, but the conversion is not always round-trip clean. For a one-off drive replacement it is faster to stay in STARTER 5.4 - the new drive and the archived project are guaranteed compatible because the tool version is unchanged. Migrate the entire machine project only when you have a planned stop of several hours.

If the spare drive is a newer V5.2 SP1 unit and the legacy machine project is on V4.7, you can keep using STARTER 5.4 + HF7 - the firmware update path covers the upgrade. You do not need to migrate to TIA Portal just to commission the spare.

Field Commissioning Checklist - Spare G120 Swap

• Confirm CU and PM order numbers on the spare match the design (or are an approved equivalent).
• Confirm the spare's firmware is acceptable for the project (or plan an upgrade).
• Upload the existing project from the failing drive and archive it.
• Set the PROFIBUS DIP switches on the new CU to the machine's address before power-on.
• Wire the PROFIBUS cable, encoder, STO, and I/O to the spare.
• Power on the CU only, run STARTER Accessible Nodes to confirm the new drive is online.
• Update firmware if required.
• Accept the power module topology if the PM was also replaced.
• Download the project to the new CU, including the Safety block (handle the default password if needed).
• Copy RAM to ROM and power-cycle to verify persistence.
• Run motor identification (p1910 = 1) with the motor cold and uncoupled if the PM was replaced.
• Run Safety acceptance test.
• Archive the final project and update the machine's documentation set.

Frequently Asked Questions