Siemens Industry Online Support
Siemens AG
Entry type: Download Entry ID: 101494917, Entry date: 11/05/2020

Simulation Tool for Soft Starters (STS)

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Simulation Tool for Soft Starters (STS) for Windows and App version (for Android and iOS) are now available for download.

Simulation Tool for Soft Starters (STS) V4.0.4.0 for Windows

What’s new in Simulation Tool for Soft Starters (STS) V4.0.4.0?    

  • It is now possible to resize the STS application window
  • New load types have been added to the pre-defined loads database
  • Switching to other languages is possible during Simulation without loss of information
  • 1LE5 Motors have been integrated into the application as part of the SIEMENS motor database
  • New alternative simulation of the application´s load based on the Trip Class
  • Minor improvements and error corrections
  • Support for Windows 7 and Windows 2008 Server operating systems has been removed. As of this version, STS can no longer be installed on PCs with these operating systems.   

What’s new in Simulation Tool for Soft Starters (STS) V4.0.3.2?  

  •  Minor improvements and error corrections

What’s new in Simulation Tool for Soft Starters (STS) V4.0.3.1?  

  •  Minor improvements and error corrections

What’s new in Simulation Tool for Soft Starters (STS) V4.0.3.0? 

  • Now it is possible to import a maximum of 500 motors at a time through the import motor template. This template is compatible as of Microsoft Office 2010 and newer
  • Suggestion of soft starters based on OPC UA server / Web server is now supported

  • Russian language support

  • In case of loads with large moment of inertia, the starting current limit is adjusted such that at least one soft starter is suggested

  • For all 3RW5 soft starters, currents were adapted to the rated current of the device, independent of trip class setting

  •  Minor improvements and error corrections

What’s new in Simulation Tool for Soft Starters (STS) V4.0.2.2? 

  • Minor improvements and error corrections

What’s new in Simulation Tool for Soft Starters (STS) V4.0.2.0?

  • Support of 3RW55 Failsafe soft starters
  • Support of 3RW50 soft starters
  • Improvement in Thermal load calculation

  • Update in UL feeder main components

  • Improvement in External bypass function calculation

  • Removal of 3RW44 soft starters from the suggestion list

  • Removal of 3RW40 S6-S12 soft starters from the suggestion list

  • Minor improvements and error corrections

Installation Notes: 

For the installation of STS V4.0.4.0 please download and run the file STS_V4_0_SP4_Setup.exe. A menu-prompted setup program guides you through the installation procedure for STS V4.0.4.0.

Please make sure that no other setup or update process is running while installing STS.

Additional information regarding the installation can be taken from the readme files.

Terms of Use:

By downloading the software application you accept the SIEMENS End User License Agreement for software applications:

 Registrierung notwendig  EULA_Software_Applications.zip (88,0 KB)

Important notes:

The main goal of this software is the correct selection of a soft starter for a respective application. For the correct parameter setting of the soft starter please refer to the user manuals and operating instructions.

STS template note:

If you are not permitted to install any software or if you have any difficulties with the simulation, you can download the STS template and enter the motor and load data. When you have done so, send the completed template back to our Support Request page https://support.industry.siemens.com/My/ww/en/requests. You will then be sent the simulation results by email.

Third-party software - Licensing terms and copyright information

You can find the copyright information for third-party software contained in this product, particularly open source software, as well as applicable licensing terms of such third-party software in the STS_ReadMe_OSS file.

Special information for resellers

The information and the license terms in the STS_ReadMe_OSS file must be passed on to the purchasing party to avoid license infringements by the reseller or purchasing party.

 Registrierung notwendig  STS_Readme_OSS_V4_0_4_0.zip (26,3 KB) (multiple languages)


 Registrierung notwendig  STS_V4_0_SP4_Setup.exe (189,5 MB)
SHA-256 checksum:   Registrierung notwendig  Code_STS_V4_0_SP4_Setup.txt (1 KB) *

Readme Files (multiple languages):
 Registrierung notwendig  STS_V4.0.4_Readme.zip (146,9 KB)

STS Template for Motor and Load Data:
 Registrierung notwendig  STS_Template_Motor_Load_data_20201102.xlsm (93,4 KB)
SHA-256 checksum:  Registrierung notwendig  Code_STS_Template_Motor_Load_data_20201102.txt (1 KB) *

Information about SHA-256:  109483101 

Simulation Tool for Soft Starters (STS) App for Android and iOS



  • Simulate a soft starter application based on your input data:
    • Environment & supply
    • Motor
    • Load
    • Starting parameters for the application
    • Additional functions
    • Starting profile
  • Select a suggested soft starter
  • Generate a report for a selected soft starter with the summary of the simulation and optional feeder main components
  • Direct access to selected soft starter data in the Siemens Industry Mall
  • Metrics: SI and Imperial
  • Languages: English, German, Chinese, Italian, Spanish, French, Portuguese, Turkish, Russian and Czech

STS App will be continuously improved and updated like the desktop version. In the coming versions we will be adding new features to match the desktop version completely.

Terms of Use:

By downloading the app for iOS or Android you accept the SIEMENS End User License Agreement for mobile applications:

Open Source components:

All open source components can be accessed here:  Registrierung notwendig  STS_App_Readme_OSS.zip (18,9 KB) 

You should have your operating system up to date. Siemens provides app updates for the up-to-date version of the operating system. Older versions of the operating system may no longer be supported.

Security information
In order to protect technical infrastructures, systems, machines and networks against cyber threats, it is necessary to implement – and continuously maintain – a holistic, state-of-the-art IT security concept. Siemens’ products and solutions constitute one element of such a concept. For more information about cyber security, please visit
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