SINAMICS S120 CU320-2 PN Performance Extension and Firmware Versions

The SINAMICS S120 CU320-2 PN control unit (article number 6SL3040-0MA00-0AA1) is the central drive controller used to operate SINAMICS S120 booksize and chassis drive line-ups over PROFINET. Whether you need to order the performance extension option, which CompactFlash (CF) card article number to specify, and how to read the firmware version are recurring configuration questions when sizing a new line-up or upgrading an existing cabinet. This reference consolidates the rules from the current Siemens D 21.3 catalog, the SINAMICS S120 List Manual, and the Siemens Industry Online Support (SIOS) firmware notes into a single engineering field guide.

1. CU320-2 PN Hardware Identification

The CU320-2 is delivered in two PROFINET and PROFIBUS variants. The PN variant carries the MLFB (machine-readable product designation code):

The PN variant is the standard choice for new booksize combinations because PROFINET is the default fieldbus for SIMOTION, SINUMERIK ONE, and the SIMATIC Drive Controller. The DP variant is retained for legacy PROFIBUS-only cells and brownfield retrofits where a PROFIBUS master is mandatory.

The CU320-2 manages up to six high-performance servo or vector axes per control unit when fully licensed. Each axis counts the Motor Module plus its connected motor, regardless of motor size or technology (synchronous, asynchronous, linear, torque). The Control Unit itself is mounted on the left side of a booksize line-up or installed as a stand-alone module for chassis drive cabinets.

2. The Performance Extension Concept

The performance extension is a runtime license that lifts the firmware cap on simultaneous axis handling. Without the license, the CU320-2 can fully control up to three axes in the standard scope of delivery. From the fourth axis onward, the firmware refuses to go into RUN and reports a license fault unless the performance option is enabled.

The license is supplied as an order code embedded on the CF card and is keyed to the CompactFlash card's serial number. It is not tied to the Control Unit's serial number; replacing the CU320-2 hardware does not invalidate the license, but cloning the CF card to a different card does. The license can also be enabled retroactively by ordering the option and applying the license key through STARTER, SINAMICS Startdrive, or the TIA Portal (when commissioning via Startdrive in TIA).

Key rules for axis counting, taken from the SINAMICS S120 Function Manual and the D 21.3 catalog chapter for CU320-2:

• A servo axis (1FK/1FT/1FW motors with SERVO control) counts as 1 axis.
• A vector axis (asynchronous or torque motors with VECTOR control) counts as 1 axis.
• An infeed (Smart Line Module, Basic Line Module, Active Line Module) does not count toward the axis budget.
• A drive object such as the control supply module (CSM), Terminal Module (TM), or Sensor Module (SMC/SME) does not count.
• Axis count is determined by the highest active axis number, not by the total number of configured axes. For example, if you configure axis 1 and axis 4 (skipping 2 and 3), the firmware still applies the > 3 rule because axis 4 is active.

3. When the Performance License Is Required

Use the matrix below to decide whether to order the performance extension when sizing a new line-up:

This clarifies a common configuration question: connecting three Smart Line Modules in parallel to a single CU320-2 PN does not trigger the performance license. The SLMs are line-side power electronics and are counted as a single infeed object regardless of physical paralleling. The license decision is driven only by the number of Motor Module axes downstream.

4. CompactFlash Card Variants and Article Numbers

The CU320-2 boots from a CompactFlash card that holds the SINAMICS firmware, the parameter set, and (when ordered) the performance license key. Siemens offers the CF card either as a spare part without firmware or as a pre-flashed card with a specific firmware version. According to the Siemens article-number reference SINAMICS S120, CU310, CU320 and CU320-2: article numbers for CF card, the article-number scheme is structured as follows:

The most commonly referenced MLFBs for the CU320-2 PN are:

The numeric jump from -0FB00- to -0FB10- indicates a later firmware generation branch. When SIZER V3.19 (and later) generates a parts list, it picks 6SL3054-0FB10-1BA0 because it is the currently active stock-keeping unit for new line-ups. Older -0FB00- cards remain fully supported for spares but are typically only shipped as replacements for legacy systems.

5. Firmware Version Identification with r0018

The currently running firmware version is exposed in parameter r0018 on the CU320-2. According to the same Siemens SIOS article (SINAMICS S120 CF card article numbers), the read-back is encoded as a single decimal integer that you decode digit by digit:

r0018 = 5020303 → FW V05.02.03.03

The decoding rule is:

Verification step at commissioning:

1. Connect STARTER or SINAMICS Startdrive to the CU320-2 over PROFINET.
2. Go online with the Control Unit (drive object CU320-2).
3. Navigate to Expert list → filter for r0018.
4. Confirm the integer matches the expected FW release for the cabinet's CF card.

6. Current Firmware Release Branch

The most recent stable release mentioned in current SIOS firmware notes for the SINAMICS S120 line is in the V5.x branch. Earlier SIOS article SINAMICS S120 firmware version 4.8 HF6 documents the V4.8 HF6 hotfix, which is the last hotfix train officially released on the V4.8 branch. For customers migrating from V4.x to V5.x, the V5.x service packs include additional Safety Integrated Extended Functions, expanded Technology Extensions (TEC) support, and updated PROFINET conformance for SIMATIC controllers such as the S7-1500 with SINAMICS Integrated (per the Firmware functions of SINAMICS Integrated documentation).

7. Axes, Line Modules, and the SIZER Workflow

SIZER for SINAMICS (formerly SIZER for SINAMICS and SIMOTION) is the engineering tool that sizes the line-up, picks Control Units, and recommends the correct CF card. The tool considers:

• Number of Motor Modules (axes)
• Type and number of Line Modules (SLM, BLM, ALM)
• DC bus coupling or parallel operation of Line Modules
• DRIVE-CLiQ topology and required Terminal Modules (TM31, TM54F, etc.)

When the axes count exceeds three, SIZER automatically appends the performance-extension order code to the CF card. This is why SIZER V3.19 outputs 6SL3054-0FB10-1BA0: it is the latest active card MLFB in that firmware generation. If you prefer to license the performance extension later, you can order the same MLFB without the F01 code and apply the license key separately.

8. Configuring the Performance Extension in STARTER / Startdrive

For retrofit scenarios where you already have a CU320-2 PN with a CF card and need to add the performance license, follow these steps:

1. Generate a license request via STARTER: Online → Target system → License manager → Perform license requirement. This writes the CU320-2's hardware serial number and the CF card serial number into a license request file.
2. Upload the request file to the Siemens Web License Manager portal (WLM) and select Performance extension for SINAMICS S120 CU320-2.
3. Download the returned license key ZIP, extract the .lic file, and copy it to the root of the CF card (or push it via STARTER's License manager → Perform licensing).
4. Cycle the Control Unit power. After reboot, the firmware re-evaluates the license and unlocks axis handling up to 6 axes.
5. Verify with parameter r0018 (firmware) and r0925 (firmware option status). Bit r0925.1 should read 1 when the performance extension is active.

9. Troubleshooting Matrix

10. Field-Proven Engineering Tips

• Always over-specify the CF card. If the cabinet may grow from 3 to 4 axes in a future retrofit, order the F01 option from the start. The cost delta is small compared to a shutdown for retro-licensing.
• Document the CF card serial number in the cabinet drawing. The license key is locked to that card. If the card fails and is replaced, you must re-license.
• Use SIZER's bill-of-material export as the source of truth for MLFBs. The catalog D 21.3 · 2017 article numbers are legacy; current SIZER output reflects the active MLFB stock-keeping units.
• For SIMATIC Drive Controller projects, the SINAMICS Integrated channel on the SIMATIC Drive Controller mirrors the same axis / license rules as a stand-alone CU320-2 PN. Refer to the SINAMICS Integrated firmware functions documentation when designing tightly coupled controller/drive systems.
• When migrating from a CU320 (non-2) to CU320-2 PN, confirm that the DRIVE-CLiQ topology star/hybrid structure is preserved. The CU320-2 PN supports the same maximum of six axes but with a higher PROFINET throughput (100 Mbit/s full-duplex per port).

11. Specifications Summary