SIMIT Simulation with S7-PLCSIM Advanced: HWCN-Export, TIA Project Ingestion, and Signal Mapping

In SIMIT Simulation Platform (V9.1, V10.x) paired with S7-PLCSIM Advanced, automating signal ingestion without manual variable creation requires either importing the compiled TIA Portal project (.ap14 / .ap15) directly or importing a hardware configuration export file (HWCN-Export). When the 'TIA-Projekt' import option is greyed out in SIMIT, it indicates that the 'Siemens TIA Openness' package was not installed with TIA Portal or that the current Windows user is not a member of the local 'Siemens TIA Openness' security group. Furthermore, for SIMIT to automatically generate simulation signals, the variables must be assigned to physical I/O modules configured in HW Config; internal memory flags (M) and data block addresses (DB) cannot be imported automatically via hardware topology and require explicit symbol table mapping.

Architecture of SIMIT PLCSIM Advanced Coupling

The SIMIT Simulation Platform models industrial process dynamics to validate automation programs prior to physical commissioning. When co-simulating with S7-PLCSIM Advanced (for S7-1500 or ET 200SP open controllers), SIMIT utilizes a high-performance shared-memory coupling (PLCSIM Advanced Coupling).

Unlike classic S7-PLCSIM, which required manual signal wiring, SIMIT can ingest hardware configurations and PLC tags automatically. It reads input and output addresses directly from the project database, creating corresponding input/output connectors in the SIMIT workspace.

The Role of HWCN-Export Files in SIMIT

When SIMIT prompts for an HWCN-Export file:

What is an HWCN File?: It is an XML-based Hardware Configuration Export file describing the station's rack slots, interface modules, distributed I/O racks, and configured I/O address ranges (PII/PIQ).
How to Generate in Classic Step 7 / PCS 7: Open HW Config in SIMATIC Manager. Select menu Station > Export.... Save the resulting .cfg / .xml file. SIMIT ingests this file to automatically build the I/O signal list.
How to Generate in TIA Portal: In TIA Portal V14 SP1 or newer, select the PLC station, go to Tools / Export, or export the station hardware configuration via TIA Openness.

Why the 'TIA-Projekt' Import Option Appears Greyed Out

When attempting to select 'TIA-Projekt' directly inside SIMIT and finding the button greyed out or inactive:

Missing TIA Openness Component: SIMIT relies on the TIA Portal Openness API to parse .ap14/.ap15 project databases. If Openness was unchecked during TIA Portal installation, SIMIT cannot interface with the project.
Windows Security Group Restriction: The logged-in Windows user MUST be an explicit member of the Siemens TIA Openness local group in Windows Computer Management. If this group membership is missing, Windows blocks SIMIT's API hook, greying out the option.
Software Version Mismatch: Direct TIA project import was officially released and stabilized in SIMIT V9.1 paired with PLCSIM Advanced V1.0 SP1 / V2.0. Using SIMIT V9.0 requires updating to V9.1.

Signal Ingestion Rules: Physical I/O vs Internal DB Variables

Engineers often report that even after successful project import, no signals appear in SIMIT:

Physical I/O Prerequisite: SIMIT's automated coupling generator only creates signals for variables assigned to physical I/O modules configured in the hardware rack (e.g., %I0.0 on an actual DI module or %Q4.0 on a DQ card). If variables exist in the PLC tag table but no physical I/O card is configured at those addresses, SIMIT ignores them!
Internal Memory Flags and DBs: Non-I/O variables—such as internal bit flags (%M0.0) or Data Block tags (DB1.DBD0)—cannot be imported via hardware topology. To exchange DB tags with SIMIT, export the variables to an Excel spreadsheet (.xlsx) and import them into the coupling's signal editor.

Comparison of SIMIT Project Ingestion Workflows

The following table compares the different methods for populating signals in SIMIT:

Ingestion MethodSource File FormatRequired ToolingCaptured Signal ScopeAutomation LevelDirect TIA Project Import.ap14 / .ap15 project fileSIMIT V9.1+ & TIA OpennessAll configured physical I/O tags100% AutomatedHWCN Configuration Export.cfg / .xml from HW ConfigSIMATIC Manager or TIAI/O address ranges (Raw bytes)Semi-AutomatedExcel Tag Spreadsheet.xlsx exported tag tableExcel / Tag EditorAny variable (I, Q, M, DB tags)Manual export/importManual Signal CreationManual entry in SIMITSIMIT Coupling EditorIndividual custom signalsFully Manual

Verification

Verify signal importation and simulation coupling:
1. In SIMIT, open the PLCSIM Advanced Coupling editor; verify that the signal list is populated with input and output tags matching the PLC I/O table.
2. Start PLCSIM Advanced; verify that the virtual instance is active with a valid IP address.
3. Click Start Simulation in SIMIT; confirm that the simulation status indicator turns solid green.
4. Force an input signal in SIMIT (e.g., set %I0.0 = 1); open the TIA Portal / Step 7 watch table online and verify that the PLC registers %I0.0 = TRUE immediately.

Limitations and Operational Precautions

If SIMIT displays the error 'PLCSIM Advanced: IP address could not be established', ensure that the Siemens PLCSIM Virtual Ethernet Adapter is enabled in Windows Network Connections and that no third-party VPN client or firewall is blocking UDP broadcast packets. S7-PLCSIM Advanced requires a dedicated runtime license managed via Automation License Manager; running without a valid license terminates simulation after a 21-day trial.

Engineer FAQ

Why is the TIA Project import option greyed out in SIMIT?

Because TIA Openness is either not installed or the logged-in Windows user account has not been added to the local 'Siemens TIA Openness' Windows user group.

Why did SIMIT import zero signals from my PLC tag table?

Because SIMIT only imports variables bound to physical I/O modules configured in HW Config. If your variables are mapped to addresses that have no physical card in the hardware rack, SIMIT skips them.

Can SIMIT simulate S7-400 and S7-1500 controllers at the same time?

Yes. SIMIT can host multiple simultaneous couplings: a classic PLCSIM coupling (or SIMIT Virtual Controller) for the S7-400, and a PLCSIM Advanced coupling for the S7-1500.