SINAMICS CU320-2 PN PROFINET Error 1230:2001 Troubleshooting

Problem Overview

Engineers commissioning a SINAMICS S120 drive lineup on PROFINET IO frequently encounter diagnostic event 1230:2001 immediately after inserting a CU320-2 PN Control Unit into the SIMATIC S7 hardware catalog and downloading the PROFINET configuration to the IO Controller. The error appears in the diagnostic buffer of the SIMATIC S7-400 CPU (for example, 6ES7 414-2XL07-0AB0 firmware V7.0) and in the online diagnostics of the CP 443-1 (for example, 6GK7 443-1EX30-0XE0 firmware V3.0). The drive never establishes an AR (Application Relationship) with the controller, STARTER/SCOUT cannot go online, and the device shows up in an unexpected position inside the project tree — often as a standalone S120 object rather than a child of the PROFINET IO system.

Event 1230 is a PROFINET IO channel-diagnostic class. The 2001 detail code is the standard "device is not reachable / AR could not be established" subclass. Although the symptoms look like a hardware failure, in the vast majority of field cases the root cause is a software/configuration mismatch between the GSDML file used in STEP 7 / TIA Portal, the firmware revision of the CU320-2 PN, and the PROFINET stack of the CP 443-1 acting as IO Controller.

Affected Hardware and Software Stack

The CU320-2 PN (order suffix 1MA01-0AA0) is a PROFINET IO Device only. Per the SINAMICS S120 Communication Function Manual (Edition 06/2019), the CU310-2 PN / CU320-2 DP / CU320-2 PN can only assume the role of a synchronization device (sync slave) within a PROFINET IO network. It cannot be an IO Controller or supervisor. This constraint governs every commissioning decision downstream.

Root Cause Analysis: Decoding Error 1230:2001

Event 1230:2001 from the PROFINET IO stack is a "station failure / AR could not be established" class error. In the TIA Portal / STEP 7 V5.5 diagnostic buffer, the entry normally appears as:

Diagnostic event  Channel diagnostics - PROFINET IO
Error type      : 1230
Error info      : 2001
Device name     : <empty or wrong name>
Device number   : <slot 0 of the IO device>
Manufacturer    : SIEMENS

The numeric structure follows the PROFINET IO alarm model. Class 0x1230 is a PROFINET IO channel-diagnostic alarm (station/AR problem), and the trailing 0x2001 is the channel-level error description. The five most common root causes seen in the field are listed below in descending frequency.

CU320-2 PN PROFINET Integration Model

The CU320-2 PN terminates the PROFINET line and exposes a fixed, GSD-described set of subslots. Unlike the CU310-2 PN, the CU320-2 PN cannot be expanded with additional CBE20 cards; the two integrated PROFINET ports (X150 P1 / P2) are the only IO interface. Inside the drive, the PROFINET stack talks to the drive object DO SERVO / VECTOR through standard SINAMICS telegrams (Standard Telegram 1, 2, 3, 4, 5, 6, 7, 9, 20, 110, 111, 220, 352 etc.).

The fixed subslot layout described in the GSDML for a CU320-2 PN is:

If the project uses free telegrams (free PZD interconnection), the configuration must agree on a byte-for-byte mapping. Mismatching the first subslot from "Standard Telegram 1, PZD-2/2" to "Standard Telegram 3, PZD-5/9" without re-aligning the IO controller mapping is a classic source of 1230:2001 after the next download.

Diagnostic Workflow

1. Capture the buffer. In STEP 7 V5.5, open PLC → Diagnostic/Setting → Diagnostic Buffer. In TIA Portal, use Online & Diagnostics → Diagnostics. Filter for entries containing "1230" and download the buffer as text for trend analysis.
2. Inspect the PROFINET device name. Connect STARTER or SCOUT online to the CU320-2 PN over Ethernet. Navigate to Communication → PROFINET → NameOfStation. The value must be byte-identical to the IO device name configured in HW Config (case sensitive, no leading/trailing blanks).
3. Check the GSDML revision. In STEP 7 HW Config, right-click the CU320-2 PN device entry → Object Properties → Identification. The "GSDML version" must be ≥ the firmware of the CU. Siemens publishes GSDML for SINAMICS S120 with the pattern GSDML-Vx.x-Siemens-Sinamics-S120-YYYYMMDD.xml. Install the latest service pack of STEP 7 to pull the corresponding HSP (Hardware Support Package).
4. Inspect CP 443-1 diagnostics. Open the online diagnostics of the CP 443-1 (EX30). The pages PROFINET IO Diagnostics → Devices and PROFINET IO Diagnostics → Ports show per-device reachability and per-port link state. Look for "Device accessible: NO" or "Port link: down".
5. Verify the topology. Use the Topology Editor in STEP 7 / TIA. Each port of the CU320-2 PN must be bound to a partner port. If the topology is not enforced (i.e., "any partner"), link failures cannot cause 1230:2001 directly, but they will produce 1230:2002 — a useful disambiguator.
6. Cross-check the DAP (Device Access Point) module. The DAP in slot 0 / subslot 0 must remain in HW Config. Deleting the DAP is a frequent user error when a user deletes "unused" modules.
7. Export/import test. As a fallback, perform an export from a known-good project and import into the failing project. The source confirms this path works on the affected hardware stack — the export/import workflow resolves the issue where direct insertion of the S120 in SCOUT into the IO system fails. Use this as a confirmation that the GSDML is intact, the device name is reachable, and the slot/submodule layout matches.

Resolution Procedure

Apply the steps below in sequence. Stop after each block and re-download the project; the error 1230:2001 will clear as soon as the AR is established.

1. Update the GSDML. Install the current HSP (e.g., HSP0280 for STEP 7 V5.5 + SINAMICS S120, or the equivalent for TIA V16+). Restart HW Config so the new device catalog is loaded. Replace the existing CU320-2 PN entry with the new revision.
2. Update the CU320-2 PN firmware. Use STARTER / SCOUT or a Web server approach to load the matching firmware. The CF card of the CU320-2 PN holds a backup image; if a downgrade was applied, the AR can fail because the new PROFINET profile expects features the older firmware does not implement.
3. Update CP 443-1 firmware. CP 443-1 EX30 firmware V3.0 is the shipping baseline, but service pack updates (e.g., V3.0.x.y) are released to address PROFINET stack issues. Use the S7-400 firmware update tool to load the latest. Validate after update that the CP still has its IP address and PROFINET device name.
4. Reassign the device name. From HW Config select Target system → PROFINET IO → Assign device name. The temporary "Assign PROFINET device name" dialog must reach the CU. If the device is not visible, switch to the network view and click the IO device node first.
5. Realign telegrams. Open the device properties → Module parameters. For every drive object on the DRIVE-CLiQ line, ensure that the PROFINET PZD set matches the configured telegram. With a S120 multi-axis lineup, this is the single highest source of slot-related 1230 events.
6. Re-download and observe. Compile, download HW Config + S7 program, and switch the CPU to RUN. The diagnostic buffer should clear within a few seconds and the CU should appear with a green status in the IO device list.

Slot and Submodule Configuration Reference

The exact configuration depends on whether the project is a single-axis S120 with one Motor Module or a multi-axis S120 with several Motor Modules on the same DRIVE-CLiQ line. The PROFINET side is independent of the DRIVE-CLiQ side: the IO controller only ever sees the CU320-2 PN, never the individual Motor Modules. Mapping from PROFINET PZD slots to drive objects is done inside the CU320-2 PN via parameter p0922 / p2079.

If a slot is left empty in HW Config but STARTER has a non-empty p0922 set, the controller will request data the CU does not publish, and the AR establishment will time out with a 1230:2001 event.

CP 443-1 EX30 Firmware and Compatibility

The CP 443-1 EX30 (6GK7 443-1EX30-0XE0) belongs to the CP 443-1 family that supports PROFINET IO with up to 128 devices. Its PROFINET stack implements:

• PROFINET IO RT (Real-Time, Class 1)
• PROFINET IO IRT (Isochronous Real-Time, Class 3) — topologically planned
• PROFINET IO shared device, shared input
• MRP (Media Redundancy Protocol) client

For SINAMICS S120, the controller-class profile is always "PROFINET IO Controller". The CU320-2 PN is a sync slave; therefore the SYNC domain in HW Config must be assigned to the CU320-2 PN by the controller. Failure to set the sync role in the project yields a configuration error that surfaces as 1230:2001 immediately on download — the controller requests the CU to be a sync master, which it cannot be.

Device Name, IP Address and Topology

The CU320-2 PN supports both DCP-based name assignment and DNS-based discovery (with the appropriate S7 firmware). For deterministic commissioning, always use DCP. The address layout should follow a strict 192.168.x.y / 255.255.255.0 scheme in brownfield projects, or the corporate scheme in greenfield. Keep the IO controller IP and the IO device IP in the same subnet.

• PROFINET device name: s120-cu320pn-01 (example, must match HW Config exactly)
• PROFINET IP address: 192.168.0.11
• PROFINET subnet mask: 255.255.255.0
• Gateway: 0.0.0.0 (default for IO devices)

Profinet naming and IP assignment should be done in this order: (1) name from HW Config, (2) reset CU to factory if name is stale, (3) re-assign name, (4) re-assign IP. The "factory reset" path in STARTER is at Commissioning → Reset to factory settings — use it when the CU retains a previous, incompatible name from a different controller.

Verification and Commissioning Tests

After resolution, perform the following verification sequence to ensure the AR is stable:

1. Diagnostic buffer clean. No new 1230 entries after 5 minutes of idle operation. The "Station OK" bit in the IO controller's status word should be set.
2. PROFINET ping. From the engineering host, ping the CU PROFINET IP. The response confirms ARP and IP reachability.
3. Online / offline comparison. In STARTER / SCOUT, go online with the drive. The state should be "Online, configuration matches".
4. Drive jogging. Use the STARTER control panel to issue a small setpoint (e.g., 50 rpm) and confirm that the actual speed tracks. This validates the full PROFINET → DO SERVO → Motor Module path.
5. Process data watch. In STEP 7, open VAT or watch table on the IO area mapped to the drive. Toggle the control word (bit 0 = ON/OFF1) and verify the state word in the IO area updates.
6. Forced error injection. Disconnect the PROFINET cable briefly. The controller should report a station-failure event, then recover automatically when reconnected. If it does not recover, the AR re-establishment is broken and indicates a deeper firmware mismatch.

Preventive Measures and Best Practices

• Always run the SINAMICS S120 firmware and the GSDML in matched revisions. A GSDML older than the firmware may implement profiles the firmware does not support, while a GSDML newer than the firmware may require features the firmware does not implement.
• Keep a master hardware support package (HSP) image on the engineering server and version-control HW Config exports. The export/import workflow described in the field report is the most reliable way to clone a working configuration to a new controller.
• Document the PROFINET device name and IP for every CU320-2 PN in the project documentation. The name is case-sensitive, the IP must be unique on the subnet.
• Avoid mixing IRT and RT on the same controller port where possible. IRT requires topology planning; mixing causes frames to be dropped.
• Reserve the device name "station-name placeholder" pattern with a sequential suffix for service replacement. When a CU is replaced, the new unit must be re-named before the AR is established.
• Run PROFINET network analysis (e.g., Profinet Commander, SINEC NMS, or Wireshark with PROFINET dissector) once per year. The error 1230:2001 is a symptom, not the disease; network health is the underlying variable.

Frequently Asked Questions