Troubleshooting SINAMICS Integrated Enables on SIMOTION D445

Problem Overview

During first commissioning of a SIMOTION D445 application with a SINAMICS Integrated drive line-up (Active Line Module ALM plus Motor Module driving a motor via DRIVE-CLiQ), the engineer observes that the drive will not pulse-enable even though every logical enable bit appears to be set. The diagnostic buffer lists four missing enables at the Motor Module:

• Enable 0 — OFF1 missing
• Enable 9 — Infeed enable missing
• Enable 17 — OFF2 missing
• Enable 30 — Speed controller inhibited

The default response is to use a BICO interconnection (BICO telegram, free telegrams 1xx, PZD manipulation, or direct p0844 / p0845 / p0852 overwrites) to force the bits high. This approach is incorrect for SINAMICS Integrated because the inter-module enable chain between the Motor Module and the Line Module is governed by a non-obvious default BICO interconnection that must not be edited. The correct procedure is to use the SIMOTION SCOUT / TIA Portal control panel "LM" button, which exercises the proper sequencing of the Active Line Module, the EP terminals, and the Motor Module in the order Siemens ships as default.

This article documents the root cause, the correct enable chain, the diagnostic procedure, and the verification steps required to bring the drive to operational state without modifying BICO defaults.

SINAMICS Integrated Architecture and SIMOTION D445

The SIMOTION D445-2 is a SIMOTION Motion Controller with an integrated SINAMICS S120 control unit (CU320-2). When the configuration is created as "SINAMICS Integrated," the CU is owned by SIMOTION and there is no separate SINUMERIK or stand-alone CU320-2 user interface; the drives appear as technology objects under the SIMOTION project. The DRIVE-CLiQ topology typically used in this scenario is:

• SIMOTION D445-2 (DRIVE-CLiQ port 0 / 1)
• Active Line Module (ALM) on DRIVE-CLiQ port 2 with an Active Interface Module (AIM) on the line side
• Motor Module on the next DRIVE-CLiQ port
• Motor with DRIVE-CLiQ encoder (or external encoder via SMC/SME)

The ALM performs controlled precharge of the DC link, supplies the Motor Module with regulated DC bus voltage, and reports its operating state back to the higher-level controller. Without the ALM being fully run-up, the Motor Module cannot release pulse enable regardless of how the local enable bits are forced. Commissioning of a SINAMICS Integrated drive line-up is described in the Creating SINAMICS Integrated documentation, and integration into TIA Portal is supported through SINAMICS Startdrive.

Enable Signal Chain in SINAMICS S120

SINAMICS S120 separates the OFF commands, operation enables, and pulse enables into distinct signals. Each signal can be sourced individually through BICO, but the factory-default source must remain unmodified for the standard ALM / Motor Module chain to function. The relevant signals and their default parameters are:

The status word r0002 mirrors the missing-enable flags. Reading r0002 displays each bit that is preventing run-up; the four bits 0, 9, 17, and 30 observed in the source correspond to:

• r0002.0 — OFF1 missing (p0840 = 0)
• r0002.9 — Infeed enable missing (p0864 = 0 or p0864 source low)
• r0002.17 — OFF2 missing (p0844 = 0)
• r0002.30 — Speed controller inhibited (p0856 = 0)

The fact that all four are reported simultaneously is the diagnostic signature that the inter-module enable chain has not been closed; specifically, the Line Module has not reached the "Operation" state, which leaves p0864 low at the Motor Module, which in turn holds OFF1, OFF2, and the speed-controller enable logically low because the open-chain protocol of SINAMICS pulls them via r863.

Root Cause: Default BICO Interconnection Between Motor Module and Line Module

The factory default for a SINAMICS S120 drive line-up with SINAMICS Integrated interconnects the Motor Module to the Line Module through a single BICO link:

Motor Module p0864 (BI: Infeed operation)  -->  Line Module r0863.0 (DO: Line module operation / ready)

Stated the other way around, the source for the Motor Module's infeed enable is read from the Line Module status. When the Line Module has not completed precharge and entered operation, r0863.0 is 0, p0864 evaluates as 0, and the Motor Module reports "Infeed enable missing." Because the missing-infeed logic also suppresses OFF1 release in many firmware versions, the OFF1, OFF2, and speed-controller-inhibited bits cascade from a single cause: the Line Module is not yet in operation.

Why Modifying BICO Signals Breaks the Enable Sequence

During manual commissioning it is common practice to force enable bits through BICO so the drive responds to a test bench without a higher-level controller. For SINAMICS Integrated, this practice is destructive because:

1. The control panel issues its own telegram sequence to the drive objects. When a separate BICO override sits on p0840 / p0844 / p0852 / p0864, the control panel's ON command does not actually close the contacts in the drive; the override wins, but the safety-relevant status flags read back inconsistently.
2. The control panel assumes default BICO. When defaults are broken, the panel will show "Drive ready" but the actual drive remains inhibited, or the panel will refuse control priority because the expected handshake bits are not where it expects them.
3. The Line Module cannot be pulsed from the Motor Module's BICO. The LM enable chain lives entirely on the Line Module object and is reachable only through the control panel "LM" button or through SIMOTION technology object commands.

Parameters That Must Remain at Default

Control Panel Commissioning Procedure

The control panel in SIMOTION SCOUT (commissioning → drive → control panel) and the equivalent panel in TIA Portal with SINAMICS Startdrive are the only commissioning tools that correctly sequence the SINAMICS Integrated enable chain. The proper sequence is:

1. Open the control panel of the drive. Confirm that the panel is communicating with both the Motor Module and the Line Module by selecting the "Assumes control priority" button.
2. When prompted, accept the safety note. The control panel will request control priority from SIMOTION for the drive object. Click "Yes."
3. Locate the "LM" button on the control panel toolbar. The LM button (button 3 in the default SCOUT layout) is the dedicated Line Module enable. Press LM first.
4. Observe the Line Module status in the diagnostics overview: it should transition from "Commissioning / Init" through "Precharge" to "Operation." Precharge typically takes 1–3 s for an ALM in the 16 kW–120 kW class; larger ALMs may require 5–10 s.
5. After the Line Module reports "Operation," tick the "Enable" checkbox on the control panel and click the green "I" (drive ON) button. This closes OFF1, OFF2, OFF3, enable-operation, infeed-enable, and speed-controller-enable in the correct order.

Once the Motor Module pulses, the control panel should show positive speed, torque, and current feedback from the encoder.

Line Module Enable via the LM Button

The LM button exists because the ALM requires additional preconditions beyond what the Motor Module's enable chain provides. Specifically, the ALM requires:

• 24 V at the EP terminal X21.3 (Enable Pulses) on the Active Line Module
• Closed hardware enable at the line filter / line contactor (if used)
• Correct phase sequence and balanced line voltage on the AIM
• Internal precharge complete and DC link voltage within ±10 % of nominal

When LM is pressed, the control panel asserts the Line Module's enable sequence: it sources p840 = 1, p841 = 1, and p842 = 1 on the Line Module object and waits for r863.0 (line module operation) to go high. Until r863.0 is high, the Motor Module's p0864 remains low and the Motor Module will report "Infeed enable missing" even if all of its local bits are set.

Diagnostic Flow for LM Button Faults

If pressing LM produces an immediate fault rather than a clean transition to operation, read the Line Module's diagnostic buffer and the missing-enable flags r0002 on the ALM. The most common causes are:

Active Interface Module (AIM) and DC Link Precharge

The Active Interface Module is a line-side filter and precharge unit that the ALM cannot operate without. It contains the precharge resistors, the line filter chokes, and the auxiliary 24 V supply tap for the ALM control electronics. When the AIM is missing, defective, or wired incorrectly, the ALM experiences uncontrolled inrush when the line contactor closes, which manifests as:

• Blown line fuses on first switch-on
• F30002 DC link overvoltage during precharge
• F30021 Ground fault on the DC link
• Repeated precharge attempts with the ALM reporting r0002 bit 9 (infeed enable missing) because r0863.0 never transitions to "Operation"

Confirm that the AIM rating matches the ALM rating. A common 6SL3xxx-series pairing for a 16 kW ALM (6SL3130-6TE21-6AAx) is the 6SL3100-0BE21-6AB0 AIM. Mismatched AIMs pass line voltage to the DC link capacitors without proper inrush limiting, producing the 400 V phase-to-phase readings on a floating scope and the voltage peaks described in the source.

EP Terminal X21 Wiring and Enable Signals

The Active Line Module's X21 terminal strip carries the hardware enable pulses input and the status outputs. The relevant pins are:

Applying +24 V to X21.3 closes the hardware gate block on the ALM IGBTs. The control panel "LM" button does not bypass this hardware enable; the engineer must wire X21.3 to +24 V externally, typically from the same 24 V rail that supplies the SIMOTION D445, before pressing LM. If X21.3 floats or sits at 0 V, the ALM will report F07840 and r863.0 will never go high.

Enable Operation Parameter p0852

Setting p0852 = 1 on the Motor Module to force "Enable operation" is also incorrect for the same reason p0864 must not be overridden: the control panel sources this bit from CW1 bit 3 (r2090.3) and the drive expects to handshake it back through r0899. Forcing p0852 = 1 outside the panel handshake leaves the drive in a state where the panel cannot read the drive's true status, and any subsequent OFF1 issued by the panel will not be acknowledged because the handshake is broken.

The correct procedure for confirming the enable operation is to read r0002 and r0003 after the LM button has been pressed. Once r0002 = 0 (no missing enables) and r0003 displays "Operation enabled," p0852 has effectively been set through the proper handshake without direct manipulation.

Fault Code Mapping for Missing Enables

For reference during diagnostics, the relevant SINAMICS S120 faults and alarms associated with the enable chain in question are:

The Safety Integrated variant of the S120 adds STO / SS1 / SBC functions that interlock with these enables. Refer to the SINAMICS S120 Function Manual Safety Integrated for the additional wiring of F-DI and the PROFIsafe telegram mapping when Safety Integrated is configured.

Step-by-Step Resolution Procedure

1. Restore every overridden BICO parameter on the Motor Module and Line Module to factory default. In SIMOTION SCOUT this is done by right-clicking the drive → Expert → Restore factory settings. Do not skip this step; partial defaults leave p0864 misrouted.
2. Verify the DRIVE-CLiQ topology matches the project. Open the topology view in SCOUT and confirm the ALM is on the expected port from the D445 and the Motor Module is on the next port downstream.
3. Verify the AIM is installed, wired, and rated to match the ALM. Confirm X1 line-side and X2 DC-link-side connections are torqued to specification.
4. Wire X21.3 on the ALM to +24 V from the same 24 V rail powering the SIMOTION D445's electronics. Confirm X21.4 is at 0 V.
5. Open the control panel of the drive. Click "Assumes control priority" and accept the safety dialog.
6. Press the LM button. Observe the Line Module diagnostic buffer; it should show a clean transition to "Operation." If a fault appears, resolve it before continuing.
7. Read r0002 on the ALM and confirm zero missing-enable bits.
8. On the control panel, tick "Enable" and click the green "I" button. The Motor Module should pulse.
9. Verify r0002 on the Motor Module reads 0 (no missing enables), r0003 reports "Operation enabled," and the encoder feedback in r0021 matches a manual turn of the motor shaft.
10. Issue a small setpoint (e.g., 50 rpm) and confirm the motor follows.
11. Release control priority back to SIMOTION. The drive is now ready to be operated by the technology objects.

Verification Procedure

After the drive is running, complete a verification checklist before handing the system over to the application programmer:

Capture a STARTER / SCOUT trace of r0002, r0003, r0021, and r0063 during a controlled ON / OFF cycle for the project documentation. This trace is the evidence that the enable chain is properly closed and is the reference against which subsequent field troubleshooting can be compared.

Frequently Asked Questions