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Entry type: Application example Entry ID: 98754973, Entry date: 08/20/2014

Compound Dosing with SIWAREX FTA in the PCS 7 environment

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  • Associated product(s)
Task Dosing operations are often required in process automation. Different methods are used depending on the requirements of the process. ...

Dosing operations are often required in process automation. Different methods are used depending on the requirements of the process.
Each method requires electronic weighing systems that vary according to the required task.
The SIWAREX FTA and SIWAREX U have been approved for use in the PCS 7 environment as an electronic weighing system.
In the process industry, a common use of the electronic weighing system is the dosing of one or more substances in a reactor.
The dosing operation should be, as much as possible:

  • accurate
  • fast
  • adaptable to various substance properties, in the limited context

The following Application Example describes the application of a compound dosage in the PCS 7 environment. Three different components are to be dosed into a reactor according to the recipe.
The dosing functions are controlled directly by the SIWAREX FTA.
In this process, the following requirements are imposed on the solution:

  • Reactor Weight (empty) = dead load
  • Accuracy ± 300g
  • Status and tolerance display after each dosing
  • Monitoring of the individual dosing steps
    (tare, coarse/fine signal, tolerance checking, dosing completed, ...)
  • Automatic optimization of cut-off points for coarse and fine signals for the individual components
  • Increased process safety by monitoring the limit value signal
    (evaluation in the AS and horn triggering on site)
  • Quality assurance by logging the time stamp, product name, time and weight
    (possible via CompactFlash card in the SIWAREX FTA)
  • Displays the current total load on location via analog value display (4-20 mA)

The current Application Example provides a template that comprises all typical components, their control system and the necessary logic.


Customer benefits
The following configuration example enables you to significantly reduce your engineering effort when using PCS 7 standard agents while improving performance. You can use this solution for both new configurations as well as for integration into existing projects. The required hardware and software products are all made ​​by Siemens and guarantee the compatibility, actuality and upgrade options you are accustomed to.

When using the SIWAREX FTA - Advanced Process Library you also get the following benefits:

  • A reduction of the knowledge necessary to develop applications
  • A decrease in the configuration effort
  • Flexible installation and customization through reusability of the program structures used
  • Guaranteed Siemens support
  • Standardized and tested solutions
  • Engineering in a familiar PCS 7 environment
  • Library module with online help (F1) in German and English
  • Setup in German and English

SIWAREX FTA - Advanced Process Library
SIMATIC PCS 7 from V8.0 Update 1


Content of downloads


Documentation "Compound Dosing with SIWAREX FTA in the PCS 7 environment"
  • Description of the application development in the PCS 7 environment
98754973_PCS7_SIWAREX_FTA_en.pdf ( 2152 KB )
PCS 7 Example project for PCS 7 V8.0 SP2
  • Contains technical functions for communication between SIWAREX FTA and AS
  • Contains SCL source files for the data conversion needed for communication between SIWAREX FTA and AS
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Further information



Manual "SIWAREX FTA PCS 7 Advanced Prcocess Library" Entry ID:
Device manual "SIWAREX FTA - Weighing Electronics for Automatic Scale" Entry ID:
Application Example "Gravimetric level measurement with SIWAREX U in the PCS 7 environment" Entry ID


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