SINAMICS S120 Performance Extension 1 License: When Required

Overview

The SINAMICS S120 drive system uses a centralized Control Unit (CU320-2 / CU320-2 DP) that executes closed-loop control, communication, and licensing for every Motor Module on the DRIVE-CLiQ bus. The number of controllable axes, the modulation type (servo vs. vector), and the resulting current controller cycle time determine whether the user must purchase the Performance Extension 1 (PE1) license and load it onto the CompactFlash (CF) card. Mis-sizing the licensing tier is one of the most common commissioning blockers on S120 Booksize systems configured for rolling mills, hoists, and other multi-axis applications.

This reference consolidates the licensing rules, the axis-count thresholds, the CF card catalog numbers, and the line-module selection criteria (Active Line Module vs. Basic Line Module + Braking Unit) that field engineers encounter when commissioning a three-axis rolling mill on PROFINET/PROFIBUS.

System Configuration Context

The reference configuration used throughout this article is a small rolling mill driven by a SIMATIC S7-300 CPU over PROFIBUS DP:

• Controller: SIMATIC S7-300 CPU 315-2DP (6ES7315-2AH14-0AB0 class)
• Drive control unit: CU320-2 DP, MLFB 6SL3040-1MA00-0AA0
• Line Module: Active Line Module with line filter and Active Interface Module
• Motor Modules: 3 × Single Motor Module Booksize, MLFB 6SL3120-1TE24-5AA3 (45 A internal-air-cooled)
• Motors: 3 × squirrel-cage induction motors, vector control
• Higher-level bus: PROFIBUS DP, 12 Mbit/s, configured with telegram 1 (PZD) or telegram 3/5 for closed-loop speed setpoints

For per-axis sizing: with 400 V line-to-line and 45 A rated output current, each axis delivers approximately S = √3 × 400 V × 45 A = 31.2 kVA apparent power, so the system totals roughly 93.5 kVA / ~75 kW of continuous mechanical output (assuming 0.85 power factor and ~95% drive efficiency).

CU320 vs. CU320-2: Why the Licensing Rule Changed

The legacy CU320 (with the older C166/SH2 DSP architecture) calculated the license requirement from the processor load and the selected current controller cycle time (T_i = 31.25 µs / 62.5 µs / 125 µs / 250 µs / 500 µs). Vector control demanded more CPU time per axis, so a 3-axis vector application frequently triggered the PE1 license requirement.

The CU320-2 (MLFB family 6SL3040-1MA00-0AA0 for PROFIBUS and 6SL3040-1MA01-0AA0 for PROFINET) uses a more powerful processor. The licensing rule for the CU320-2 is no longer coupled to the raw load; instead it follows a fixed axis-count table per modulation type. A CU320-2 with up to 3 vector axes or 6 servo axes does not require a Performance Extension license. The fourth vector axis (or seventh servo axis) is what trips the requirement.

Performance Extension 1 License: Catalog Numbers and Activation

The Performance Extension 1 license is delivered electronically as a license key bound to the serial number of the CompactFlash card. The relevant catalog numbers are:

Activation procedure:

1. Order the license through the Siemens License Portal at Siemens SINAMICS Licensing Overview and bind it to the CF card serial number printed on the card label.
2. Insert the CF card into the CU320-2 and power up the Control Unit with the 24 V supply.
3. In STARTER (or Startdrive in TIA Portal V16+), go to Online > Drive Unit > Licenses. Click Activate; the Web License Manager writes the key to /OEM/SINAMICS/KEYS/ on the CF.
4. Verify with CU parameter r7843[0] = current License Level, and r7843[1] = required License Level. The two values must be equal.

CompactFlash Card: Required Even Without a License

A frequent mistake is to omit the CF card from the BoM because no Performance Extension is required. The CF card is mandatory on every S120 Control Unit; it stores the firmware, project, and the license keys (when present). Booting the CU320-2 without a CF card puts the drive into a non-fatal warning state (F01005 / A01005 depending on firmware), but the drive will not run any axes.

Vector vs. Servo Control: Effect on Axis Count and License

Vector control is recommended for continuous-duty applications (rolling mills, paper machines, mixers) that require high torque accuracy at low speed, full torque at zero speed, and good load-step response without encoder feedback. The current model runs a flux model plus speed observer; this consumes more DSP time per axis than servo control.

Servo control is intended for high-dynamic positioning with a pulse encoder or resolver. The control structure is leaner because the rotor position is measured directly, so a CU320-2 can run up to 6 servo axes on a single Control Unit without a license.

If the rolling mill application does not require a holding torque at zero speed (i.e., the load always rotates when energized), servo control can free up licensing headroom and reduce the current controller sampling time from 250 µs (vector default on Booksize) to 125 µs or even 31.25 µs, improving dynamic response. For a 3-axis mill, however, both modulation types fit within the license-free envelope, so the choice becomes one of dynamics, encoder availability, and motor type.

Line Module Selection: Active Line Module vs. Basic Line Module + Braking Unit

For a rolling mill, regenerative braking is unavoidable during mill deceleration and pinch-roll opening. The line-side architecture must either return the energy to the grid or dissipate it as heat. The two practical architectures are:

For a 70–100 kW rolling-mill drive train, the Active Line Module is the preferred solution because:

1. It eliminates the Braking Module and Braking Resistor, removing a sizeable cabinet heat load and periodic resistor-element replacement.
2. It actively regulates the DC link voltage, providing better immunity to line dips (LVRT / FRT) than a passive diode BLM.
3. The Smart Line Module is functionally similar but is not available in the 70 kW power class in Booksize format; the SLM tops out around 55 kW (6SL3130-6TE25-5AA0). Above that, the ALM (6SL3130-7TE28-0AA3 for 80 kW, 6SL3130-7TE31-2AA3 for 120 kW) is the only regenerative Booksize option.

Current Controller Cycle Time Selection

The current controller cycle time (T_i) is configured in p0115[0] on the CU320-2 for vector axes and p0115[1] for servo axes. Standard Booksize values:

• Servo: 31.25 µs, 62.5 µs, 125 µs
• Vector: 125 µs, 250 µs, 500 µs

Reducing T_i halves the available CPU time per axis. On the CU320-2, the licensed maximum is set by r7843 (License Level). If the chosen T_i pushes the load past the licensed limit, the drive raises fault F01004 — “Internal software error, drive object not on a licensed sampling time” — and the affected axis will not enable.

Commissioning Procedure for a 3-Axis Rolling Mill

1. Insert the CF card (6SL3054-0AA00-1AA0) into the CU320-2 DP. Power the Control Unit from a clean 24 V supply (PELV, ≥ 5 A).
2. Connect DRIVE-CLiQ from the CU320-2 to each Motor Module and to the Active Line Module using shielded DRIVE-CLiQ cables. Use the prescribed topology — CU → ALM → MM1 → MM2 → MM3 is the default Booksize daisy-chain.
3. Wire the PROFIBUS DP cable from the CPU 315-2DP to the CU320-2 X126 port; set the PROFIBUS address using the rotary switches on the front of the CU (e.g., address 4).
4. Open STARTER (matching the firmware on the CF card, e.g., V5.2 SP3). Create an offline project with the CU320-2 DP and the three Motor Modules. Select Insert Drive Object > Vector for each axis.
5. Configure the drive objects: motor code from the motor rating plate, encoder type (resolver / HTL / TTL), current limit, mechanical limits.
6. Set telegram mapping: each axis to Standard Telegram 3 (8 PZD) for speed setpoint from the S7-300. Configure the S7-300 hardware configuration (HW Config) with the matching PROFIBUS slave GSD file (SIEM80FE.GSD for older releases, SIEM8170.GSD for V5.x firmware).
7. Download the project to the drive. Run Commissioning > Automatic Optimization on each axis (encoder adjustment, motor identification, speed controller tuning, current setpoint filter). Accept the test signal travel of 60° electrical for motor ID.
8. Wire the Safety functions (if used) per SINAMICS S120 Safety Integrated Function Manual (PROFIsafe over PROFIBUS, or via TM54F).
9. From the S7-300, exercise each axis via the SFC 14 / SFC 15 (DPRD_DAT / DPWR_DAT) blocks. Verify ramp-up, steady-state speed, and controlled deceleration under regeneration.

Verification Checklist

• r7843[0] = r7843[1] — License level matches requirement
• r9771[0] = FFFF FFFF — No active Safety faults (if Safety is configured)
• r3996[0...2] shows the configured telegram for each axis

• CU online diagnostics → Topology shows all four DO (1 ALM + 3 MM) in green

• Each axis completes the first Encoder adjustment and Motor identification routine without raising F07900 (motor ID) or F31117 (encoder)
• PROFIBUS: S7-300 diagnostic buffer contains no F-IDs; SINAMICS CU logs no A08502 (sign-of-life failure)
• Regenerative test: roll deceleration returns energy to the grid; DC link voltage (ALM display r0070) stays within tolerance; no F30002 (DC link overvoltage)

Troubleshooting Matrix

Related Parameters for Quick Reference