Creating Custom Structured Connector Types in SIMIT Component Type Editor (CTE)

To pass composite structured data between custom simulation models in SIMIT V8.1 Component Type Editor (CTE)—similar to standard FLOWNET or Measure connector types—create a user-defined connection type directly within the CTE interface. Standard connector types (.simcon files located under SIMIT\connection\Flownet) are binary-compiled and cannot be edited with external text editors. In the CTE, expand Connectors -> Connection Types -> User-Defined Connection Types -> Global Connection Types, select 'Create New Connection Type', define the structure fields and units, and restart CTE to update the component palette.

SIMIT Connector Types and Structural Data Exchange Architecture

In SIMIT Simulation Platform (V8.1 and V9.x), the Component Type Editor (CTE) allows automation engineers to develop custom physical and algorithmic simulation components using behavioral description code. Standard components exchange primitive signals (single boolean, integer, or floating-point values).

However, complex process modeling—such as hydraulic pipelines, thermodynamic heat exchangers, and electrical distribution—requires transferring composite data packets across a single graphical connection line. SIMIT manages these composite connections using Connector Types (such as FLOWNET fluid properties: Pressure, Enthalpy, Mass Flow; or Measure structures). Custom modeling frequently demands custom user-defined structured connectors.

Proprietary .simcon File Architecture vs CTE Internal Editors

Engineers attempting to inspect or modify existing connection types often discover .simcon files inside the installation directory (C:\Program Files (x86)\Siemens\Automation\SIMIT\connection\Flownet). Attempting to edit .simcon files using Notepad or XML editors fails because they are proprietary binary-serialized archives.

SIMIT provides a native graphical interface within CTE to generate and manage connection types. Creating, modifying, or copying connector definitions must be executed through the CTE navigation pane under Global Connection Types. Once saved, CTE automatically compiles the binary structure into the local project environment.

Data Types and Variable Parameters for Custom SIMIT Connectors

The table below details data types, physical dimensions, and structural properties configurable in SIMIT CTE connection types:

Structure ParameterSupported Data TypesPhysical Dimension / UnitPurpose in Simulation ModelThrough VariablesREAL, DOUBLEMass flow ($kg/s$), current ($A$)Flow-conserving physical variables that balance at nodes.Across VariablesREAL, DOUBLEPressure ($bar$), voltage ($V$), temp ($K$)State potential variables shared across parallel connections.Status / Info BitsBOOLEAN, BYTEDimensionlessOperating mode, reverse flow flags, valve limit switches.Physical UnitsSIMIT Unit CatalogStandard SI or Imperial unitsEnsures automated unit conversion across model boundaries.DirectionalityIn, Out, InOut (Bidirectional)Flow vectorDetermines topological calculation order in simulation solvers.

Step-by-Step Procedure to Create and Deploy Custom Connector Types

Launch Component Type Editor: In SIMIT V8.1, open your simulation project. In the navigation tree, open the Component Type Editor (CTE).
Navigate to Connector Management:
- In the left pane, expand Connectors (Anschlüsse).
- In the right window, navigate to Connection Types (Verbindungstypen).
- Expand User-Defined Connection Types (Eigene Verbindungstypen) -> Global Connection Types (Globale Verbindungstypen).
Create New Connection Type:
- Right-click and select Create New Connection Type (Neuer Verbindungstyp erstellen).
- Enter a distinct symbolic name (e.g., CustomFluidStruct).
Define Structural Members:
- Right-click the newly created type -> select Open (Öffnen). SIMIT creates an editable working buffer.
- Add structural variables: specify Name, Data Type (REAL, BOOL), Dimension (Pressure, Temperature, Flow), and Default Unit.
- Confirm entries and press Enter to compile.
Restart CTE to Flush Cache:
- Close the Component Type Editor and relaunch it. (Restarting is mandatory to purge obsolete internal cache handles and refresh the catalog).
Assign Connector to Custom Component: In your component's behavioral code, declare connector pins utilizing the new CustomFluidStruct type.

Verification

Verify custom connector behavior through the following milestones:
1. In CTE, create a simple test component with an output pin typed as CustomFluidStruct and a second component with a matching input pin.
2. Drag both components onto a SIMIT simulation diagram: connect the pins with a single connection line: confirm that SIMIT allows the connection without type-mismatch warnings.
3. Start simulation runtime: monitor the connection line in online mode: confirm that all sub-structure fields transmit values simultaneously.

Limitations and Operational Precautions

When deleting or renaming connection types in CTE, SIMIT may display ghost entries in the selection list until the application is completely restarted. Always restart SIMIT following structural connector modifications. Furthermore, connection types created under 'Local Connection Types' are confined strictly to the active project; always define shared structures under 'Global Connection Types' if models are distributed across multiple simulation workspaces.