Managing Model Instances and Central Template Updates in SIMIT V8.1

In SIMIT V8.1, automatically propagating modifications from a central template across all placed instances depends on whether models were instantiated as Graphic Macros or Component Type Editor (CTE) components. Graphic Macros are copied statically onto simulation diagrams; modifying the source macro file does not retroactively update placed instances. Conversely, custom components developed in the SIMIT Component Type Editor (CTE) behave as true object-oriented type definitions. Modifying and compiling a CTE component updates the underlying behavioral equations globally across all instances via 'Update Components', while programmatic bulk replication of repetitive equipment is best managed using SIMIT Automatic Model Construction (AMC).

Template Inheritance Paradigms: Macros vs CTE Components

Simulation engineers building complex process models in SIMIT V8.1 utilize two primary modularization mechanisms:

Graphic Macros (*.smac): Composite graphical assemblies consisting of multiple interconnected library blocks (e.g., a motor drive macro combining a drive model, feedback delays, and limit switches). Macros simplify drawing repetitive circuits on simulation sheets.
Component Type Editor Components (*.simtype): Monolithic behavioral modules defined by discrete differential equations, internal state vectors, and connection pins compiled in CTE.

Why Graphic Macros Do Not Update Automatically

The table below contrasts the instantiation and update behavior between Macros and CTE Components:

Modularization FeatureGraphic Macros (*.smac)CTE Components (*.simtype)Instantiation ModelCopy-Paste by Value: Instantiating a macro copies raw blocks onto the canvas.Instantiate by Reference: Instances point to the central type definition in the library.Retroactive UpdatesUnsupported: Modifying the macro file leaves existing diagram copies unchanged.Supported: Saving changes in CTE automatically updates all placed component instances.Search and ReplaceLimited: Text find/replace cannot alter underlying macro topology.Automatic: Equation and algorithm changes apply globally upon project compilation.Pin / Terminal ChangesManual re-wiring required if macro blocks change.Type update prompts for reconnection if terminal signatures are modified.

Workflow for Centralized Updates via CTE Components

To establish true object-oriented template inheritance in SIMIT V8.1:

Package the repetitive process logic inside a custom component using the Component Type Editor (CTE).
Place instances of this CTE component across simulation diagrams, interconnecting signal terminals.
When logic modifications are required (e.g., revising a valve opening characteristic or pump curve):
- Open the source component in CTE.
- Update the mathematical equations in the Cyclic Calculation tab.
- Save the component (File -> Save).
Return to the main SIMIT simulation project: SIMIT detects the updated timestamp and prompts:
Component types have been modified. Do you want to update all instances?
Click Yes: all placed instances immediately inherit the revised calculation logic.

Bulk Instantiation and Parameter Management via SIMIT AMC

For facilities containing hundreds of identical valves, pumps, or conveyors, manual macro placement is inefficient. Siemens provides Automatic Model Construction (AMC):

Spreadsheet-Driven Generation: Component instance names, controller I/O addresses, and physical parameters are defined in Microsoft Excel.
Automated Build: AMC reads the Excel matrix and generates simulation sheets, placing CTE components and binding I/O signals automatically.
Bulk Synchronization: If engineering parameters change, updating the Excel table and re-running AMC re-synchronizes all placed instances across the entire simulation multiproject.

Verification

To verify that template modifications propagated across all instances:

In CTE, modify an internal calculation parameter (e.g., change default valve stroke time from 5.0 to 12.0 seconds).
Save the component in CTE and return to SIMIT.
Confirm that SIMIT displays the component update dialog and completes synchronization.
Open two separate simulation sheets containing instances of the component.
Start the simulation: verify that both instances exhibit the newly updated 12.0-second stroke behavior.

Limitations and Operational Precautions

Operational boundaries for SIMIT template updates:

Connector Signature Changes: If you delete or rename a connection pin on a CTE component, updating instances will sever existing diagram connection lines; preserve connector names to maintain topological integrity.
Macro Replacement Overhead: If relying on graphic macros, updating logic requires manually deleting old macro instances from diagrams and re-dragging the updated macro file.
Version Migration: When upgrading from SIMIT V8.1 to V9.x or V10, verify that custom CTE component libraries are recompiled to match the updated simulation kernel.

Engineer FAQ

Why don't placed SIMIT macros update when I edit the macro file?

SIMIT graphic macros are pasted as static, independent copies of graphic shapes and blocks. They maintain no active database link to the source macro template file.

How can I achieve true type-instance inheritance in SIMIT?

Use the Component Type Editor (CTE) to build custom components (*.simtype). Instances of CTE components maintain an active type relationship and update automatically when the type is modified.

Can search and replace update blocks inside existing macros?

Search and replace can update signal names and text properties across diagrams, but cannot alter the internal block wiring or structure of already-placed macros.