Sinamics S120 CU320-2DP SMC10 Drive-CLiQ Wiring and Commissioning

Overview

The Sinamics S120 Booksize drive system centered on a CU320-2DP Control Unit is one of the most flexible Siemens motion platforms, but it is unforgiving when the Drive-CLiQ topology, sensor module, and motor feedback type do not match. This reference documents the correct wiring and commissioning path for a system built from:

• 1 × CU320-2DP Control Unit (6SL3040-1MA01-0AA0 family)
• 2 × Single Motor Module 6SL3120-1TE21-8AA4 (Booksize, 18 A, internal air cooling)
• 2 × SMC10 Sensor Module (6SL3055-0AA00-5AA2) – for resolver feedback only
• 2 × TM31 Terminal Module (6SL3055-0AA00-3AA1)
• 2 × 1FT6084-8AF71-4BA3-Z servo motor
• External DC link at 531 V with separate 24 V supply for the CU

The most common failures on this exact configuration are (a) selecting the wrong SMC family for the encoder type, (b) wiring the resolver cable between a male DB9 on the motor and a female DB25 on the SMC10, and (c) missing the EP / Enable Pulses signal when the system is operated without a Line Module. The sections below cover all three with pin tables, wiring diagrams, and STARTER diagnostics.

Prerequisites

• STARTER (Sinamics Startdrive or SIMATIC STEP 7 / STARTER V5.x) installed on a PG/PC with DRIVE-CLiQ interface or USB-to-Ethernet adapter.
• DRIVE-CLiQ cable 6SL3060-4Axx0-0AA0 (cross-section 0.38 mm², shielded). Lengths from 0.11 m to 75 m are available.
• Resolver cable with DB25 female on the SMC10 end. The SMC10 ships without a resolver cable, so a custom cable is required when the motor has a DB9 connector.
• 24 V DC supply for the CU electronics (X124 pin 1 = 24 V, pin 2 = M; capacity ≥ 3 A).
• DC 531 V link, sourced either from a Smart Line Module / Active Line Module or from an external DC bus.
• Firmware V5.x or higher on the CU320-2DP; SMC10 minimum 2.4. Verify in STARTER → Drive Unit → Version Overview.

Drive-CLiQ Topology

Drive-CLiQ is a serial real-time ring. Each node is auto-addressed; the order is not arbitrary because the control unit numbers the slots in the sequence it polls them at power-up.

1. CU320-2DP – port X100–X103. Leave port X100 for the next component downstream of port X101 (internal rule: odd ports are downstream, even ports return).
2. TM31 – connect to CU port X101. The TM31 provides DI/DO/AI/AO expansion for cabinet-level signals.
3. Single Motor Module 1 – connect to TM31 port X500 OUT.
4. SMC10 for Motor 1 – connect to Motor Module 1 port X500 OUT. The resolver cable then goes from SMC10 X520 to the motor resolver connector.
5. Single Motor Module 2 and its SMC10 form the rest of the ring, returning to the CU at port X102 or X103.

Topology rule: every Motor Module has exactly two adjacent Drive-CLiQ neighbors. Do not daisy-chain SMC10 off another SMC10 – always off a power module.

SMC10 Resolver Pin Assignment (DB25 Female)

The SMC10 X520 connector is a 25-pin D-sub female. The 1FT6084 resolver (where present) and many retrofit resolver motors use a male DB9. The mapping below is the field-proven cross-over and matches the SMC10 manual SMC10 Sensor Module manual (A5E00295350).

Pins 7, 8, 9, 11, 12, 13, 16–24 on the SMC10 connector are reserved and must remain open. The cable shield bonds to pin 25 on the SMC10 side and to the DB9 metal backshell on the motor side. Use a twisted-pair cable with individual pair shielding (e.g., Siemens 6FX8002-2CA31 or equivalent) – do not untwist beyond 20 mm when terminating.

TM31 Control Wiring for the EP Signal and Run Enable

Without a Line Module, the S120 has no automatic OK signal. The drive needs two enables before pulses can be released:

1. OFF1 / ON command – from PLC on DI 0 of TM31 or bit r0898 from CU.
2. EP (Enable Pulses) – the hardware release; bit r0899.12 must be TRUE.

Because there is no Active Line Module in this system, the EP signal must be wired externally. The DC-link Ready relay of the external 531 V supply or the motor contactor OK contact must be wired to a free DI on the CU (X122 or X132) or on the TM31, then routed through parameter p0840 (BI: ON/OFF1) and p0862 (BI: Enable Operation / EP).

Route the analog inputs through the correct CU parameters:

• Voltage speed reference: AI0 → p1070[0] = r4055[0] (main setpoint).
• Current torque limit / supplementary setpoint: AI1 → p1503[0] = r4055[1].
• If the PLC only supplies a current loop, set AI0 mode jumper on TM31 to C (current, 4–20 mA).

STARTER Topology Verification and Online View

1. Open STARTER, create a new project with the matching CU320-2DP order number.
2. Insert components manually from the catalog, or Automatic configuration with the drive powered. Manual mode is safer if the motor order code must be matched.
3. Right-click the drive unit → Go online. STARTER now performs a topology comparison.
4. Open Topology view. Compare offline (project) against online (actual). Mismatched components show in red with a numeric state code.

If the online topology shows the SMC10 but STARTER has an SMC20 configured, every drive object under the SMC10 fails commissioning. The drive returns fault F01357 (topology: component not assigned) plus F08090 (drive object not assigned). Clear them by aligning the offline configuration to the actual hardware and re-download.

Common Faults and Resolution Matrix

Step-by-Step Commissioning Sequence

1. Power on 24 V DC supply to the CU. LED on CU should show green READY, optional SF red off.
2. Insert Drive-CLiQ cables per topology table; verify ring is closed (each LED on every DRIVE-CLiQ port: green steady = OK, green flash = active, off = not connected).
3. Connect PG/PC to CU port X127 (service) or to the PLC if connected by PROFIBUS / PROFINET. Establish online connection.
4. Run STARTER → Automatic Configuration. Accept the discovered topology; reject only items you intentionally omit.
5. Enter motor data from the 1FT6084 rating plate: p0301 (motor code) for 1FT6084-8AF71 is 1FT60848AF, p0304 / p0305 rated voltage/current, p0311 rated speed, p0314 pole-pair number (4 for 1FT6 in 8-segment frame), p0316 motor inertia. If using Siemens motors select p0301 = motor code, the rest is filled automatically.
6. Encoder selection: set p0400[0] = 2002 for resolver (resolver on SMC10) or 2001 for incremental sin/cos on SMC20.
7. Run motor identification: p1900 = 2 (rotating measurement, with safety clearance) or p1910 = 1 (static measurement, no rotation). Apply 24 V ON, then close OFF1, then start identification from STARTER's Commissioning screen.
8. After identification, set p1121 deceleration ramp ≥ 5 s, set p1082 maximum speed to motor rated speed, set p2000 reference speed = rated speed.
9. Run a slow-speed jog: STARTER → Control Panel, setpoint = 5 %, enable ON/OFF1 and EP, observe motor rotates forward.
10. Hand over to PLC: set p0840 to the PLC bit address, set p0862 to the EP bit.

Encoder Type Reference – SMC Selection Table

Drive-CLiQ Diagnostic LED Meanings

Verification Checklist before PLC Hand-over

• All Drive-CLiQ LEDs green steady on every component.
• STARTER online = offline; topology difference list empty.
• No F-class faults active in the diagnostic buffer; A-class warnings only acceptable if documented.
• Motor identification successfully completed (r0047.30 = 1 if p1910 was used).
• Current controller bandwidth ≥ 2000 Hz and speed controller bandwidth within Siemens datasheet (300–800 Hz for 1FT6).
• PLC / STARTER control panel jog test: motor follows setpoint with correct sign and reaches rated speed with torque < 0.5 × T_max at no load.
• EP signal latches and unlatches cleanly when 24 V is removed from the configured DI.

Frequently Asked Questions