SINAMICS G120C PROFINET Setup with Safety Integrated STO

Overview

The SINAMICS G120C is Siemens' compact modular frequency inverter for basic and mid-range drive tasks. It supports PROFINET as a standard communications interface and offers integrated Safety Integrated basic functions (STO, SS1) without requiring additional safety hardware on the drive side. This reference covers a complete commissioning workflow in TIA Portal V13 SP1: firmware upgrade, PROFINET device and topology configuration, free telegram 999 mapping with BICO, Safety Integrated STO activation, acceptance test execution, and torque actual value scaling.

The workflow assumes a CPU that supports PROFINET IO Controller (S7-1500, S7-1200, ET 200SP CPU, or equivalent) and uses the Startdrive V13 SP1 HSP (Hardware Support Package) version 4.7.3 to expose the G120C device object in the TIA Portal device catalog. The same procedure applies to G120C PN variants (6SL3210-1KE1x-xxxx-x) using the G120C Control Unit with PROFINET interface.

Prerequisites

Step 1 - Firmware Upgrade to V4.7.3

1. Install HSP V4.7.3 for Startdrive V13 SP1 on the engineering station. Restart TIA Portal so the new G120C FW 4.7.3 device version appears in the device catalog.
2. Prepare an SD card (256 MB to 2 GB) with the firmware files placed in the root directory.
3. Power off the G120C. Insert the SD card into the drive's card slot (underside of the Control Unit).
4. Power on the G120C. The drive detects the firmware on the SD card and performs the update automatically. The RDY LED flashes green/orange during the update; do not remove power until the RDY LED returns to a steady state.
5. After the update completes, verify the firmware version in parameter r0018 or via the drive BOP-2/IOP-2 operator panel: r0018 must read 4.7.3.

Step 2 - Create the Project and Add Devices

1. Open TIA Portal V13 SP1. Create a new project. Add a SIMATIC S7-1500 CPU (or your target controller) from the device catalog. The CPU's PROFINET interface becomes the IO Controller.
2. Add the SINAMICS G120C drive. In the device catalog navigate to Drives & starters → SINAMICS G120C → PN and select the firmware version V4.7.3. Drag the device into the project tree.
3. Add any HMI panels or additional PROFINET devices that must participate in the same PROFINET network.

Selecting the correct firmware version in the device catalog is critical. A mismatch between the configured firmware and the actual drive firmware is the most common cause of a failed download. Always recheck r0018 on the physical drive before assigning it to a device in the project.

Step 3 - PROFINET Topology and Network View

1. Open Devices & Networks → Topology view. Connect every port of the IO Controller, the G120C, and any switches so that the topology mirrors the physical cabling. The PROFINET topology editor requires each PROFINET port to be assigned to the neighbor that the port is physically wired to. Even a missing neighbor port can prevent the drive from going into cyclic data exchange.
2. Open Network view. Drag a PROFINET connection from the PLC port to the G120C port. The G120C is assigned to the IO Controller.
3. Confirm the G120C appears in the IO Controller's distributed I/O. Its assigned PROFINET device name and IP address must match the values that will be assigned to the physical drive later.

Step 4 - Commissioning Wizard and Motor Data

1. Select the G120C in the project tree and open Parameters → Commissioning. Run both the standard commissioning wizard and the expert commissioning wizard. The standard wizard covers most motor nameplate data; the expert wizard exposes additional parameters.
2. Enter motor data exactly as printed on the motor nameplate: rated power, rated voltage, rated current, rated frequency, rated speed, and rated power factor (cos φ).
3. Set ramp-up time (p1120) and ramp-down time (p1121). Typical starting values for general-purpose applications are 10 s up and 10 s down; tighten for high-inertia loads and loosen for soft-start requirements.
4. Select telegram [999] Free telegram configuration with BICO. Telegram 999 exposes all PZD slots for free mapping through BICO technology, which is required when the application needs a non-standard word count or non-standard signal assignment.

Step 5 - Device Configuration: Communication Parameters

1. Double-click the G120C in the project tree to open Device configuration.
2. Open the PROFINET interface node and assign: IP address, Subnet mask, PROFINET device name, and PROFINET device number. The device name and IP must match the values from Step 3.
3. Open Cyclic data exchange. The currently selected telegram is shown; for this workflow it must be Free telegram (telegram 999).

Step 6 - Configure Cyclic Telegram Word Count

The free telegram allows up to 8 PZD words in each direction. Configure the input and output lengths to match exactly what the application uses.

1. In Cyclic data exchange set Input length = 4 words and Output length = 2 words.
2. Open Partner data area and assign the IO addresses. A safe starting range is I1000..I1007 for inputs and Q1000..Q1003 for outputs. Verify that these addresses are not used elsewhere in the PLC program.

Step 7 - Functional View: Safety Integrated Basic Functions

1. In the drive project tree, open Parameters → Functional view.
2. Activate Safety Integrated. Select Basic functions. The basic functions supported by the G120C with firmware 4.7.3 include STO (Safe Torque Off) and SS1 (Safe Stop 1, time-controlled).
3. Select the control type. The two options are via terminals (the on-board safety digital inputs on the Control Unit) and via PROFIsafe (safety over PROFINET). For this workflow, via terminals is used.
4. Configure the Test stop / forced checking procedure. The Test stop is a mandatory periodic check that exercises the safety path to detect latent faults. Increase the timer to 8000.00 hours if the application permits; this is the maximum interval allowed by the firmware and reduces the frequency of required operator interventions.

Step 8 - Communication Settings: PZD Direction Mapping

1. Open Communication settings → Receive direction (PLC → drive). Two words must be selected: Control word and Main setpoint. The first word (control word) is auto-selected and appears empty; the second word is also auto-selected. Confirm both are bound to the PZD slots that map to the PLC's Q1000 and Q1001.
2. Open Communication settings → Transmit direction (drive → PLC). Four words must be selected:
   • Word 1: Status word (auto-selected)
   • Word 2: Speed actual value NIST (auto-selected)
   • Word 3: Torque actual value from r0080
   • Word 4: Actual fault code from r2131

Step 9 - Download to Device

1. Select the G120C in the project tree.
2. Click Go online → Download to device.
3. Select the correct G120C from the accessible nodes in the search dialog. Confirm the PROFINET device name matches the configuration.
4. Trigger the download. After completion, use Copy RAM to ROM (Save to EEPROM) to make the configuration non-volatile on the drive.

Step 10 - Safety Commissioning and Acceptance Test

After the first download with Safety Integrated enabled, the drive raises the alarm F01600 (acceptance test required) or the equivalent message on the BOP-2/IOP-2. This is expected behavior: the safety path has not yet been accepted for production use. Run the safety commissioning sequence below to clear the alarm.

1. Go online to the G120C.
2. Open Parameters → Functional view → Safety Integrated.
3. Click Start safety commissioning.
4. Enter the safety password. The default is 0. Siemens recommends assigning a project-specific password (p9761) before releasing the drive to production; for the initial commissioning workflow the default is acceptable.
5. Click Start safety commissioning a second time. This is intentional: the first click enters commissioning mode, the second click confirms and locks in the values.
6. When prompted, confirm Save settings to EEPROM (ROM). The drive's non-volatile memory and the safety CRC are updated.
7. Reset any active faults. Two equivalent methods are available:
   • From the PLC: issue the fault acknowledge through the control word (bit 7 of STW1 rising edge).
   • From TIA Portal: project tree → current drive → Online & diagnostic → Active alarms → Faults button.

Step 11 - Torque Actual Value Scaling in the PLC

The drive delivers the torque actual value in r0080 as a normalized integer in the range ±16384 (corresponding to ±100 % of the reference torque). The reference torque is set in p2003. To obtain a scaled real-world torque in the PLC, use the formula:

Torque_actual_Nm = INT_TO_REAL(r0080_word) / 16384.0 * p2003

Where:

• r0080_word is the PZD word 3 received from the drive (the 16-bit signed integer representation of torque actual value).
• p2003 is the reference torque in Nm. Read it from the drive parameter list. To find p2003 in TIA Portal, open the drive Parameters editor, switch to Parameter view, and at the lower-left corner enable Display extended parameters to make expert-level parameters visible.

Verification and Troubleshooting Matrix

Field Commissioning Notes

Three operational points consistently surface during field deployment of a G120C on PROFINET with Safety Integrated:

1. Always reconcile the configured firmware version in TIA with the physical drive before assigning the device to a project. A version mismatch either blocks the download or silently downgrades the drive's parameter set. Read r0018 from the BOP-2 before clicking "Assign device".
2. The expert commissioning wizard is not optional for free-telegram configurations. Motor power factor and several BICO source selectors that are needed for non-default signal mapping live only in the expert tree. A standard-wizard-only commissioning is the most common root cause of "drive runs but does not reach rated torque" support calls.
3. The acceptance test record is a regulatory document, not a checkbox. For machinery that falls under EN ISO 13849-1 PL d or higher, the acceptance test report must be signed and retained for the lifetime of the machine. The drive's safety CRC and commissioning timestamp (r9780, r9781, r9782) must be recorded in the report so a future audit can verify the safety configuration has not been altered.

Frequently Asked Questions