SIWAREX WP251 weighing module
SIWAREX WP251 electronic weighing module

Weighing Module

SIWAREX WP251 is a very compact weighing module for dosing and batching tasks. The module can be installed seamlessly with the SIMATIC S7-1200 or operate as a stand-alone unit.

SIWAREX WP251 Catalog Specifications

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As part of the SIMATIC S7-1200 basic controller family the module integrates seamlessly into TIA-Portal or in stand-alone mode without a SIMATIC CPU.


Diverse options are available for commissioning. The SIWAREX WP251 function block enables full access to all parameters of the SIWAREX WP251 and the downloadable example application "ready-for-use" provides calibration and operation options for the scale - without any additional programming


The integration into TIA-Portal allows an activation of user interfaces and an upload to all available SIMATIC operator panels. In combination with a SIMATIC S7-1200 basic controller, all customer and application specific requirements can be realized easily.


In the stand-alone mode all parameters and functions can be accessed and edited via the on board Modbus RTU or Modbus TCP/IP interface. In this case a PC or any Modbus-compatible device can be directly connected and used for operation.


Beside that the SIWAREX WP251 offers a trace function. All traced process values and status information of the scale can be illustrated and analyzed with SIWATOOL V7 and, if required, edited in spreadsheets.


  • Uniform structure and universal communication through the integration in S7-1200

  • Four digital in- and outputs, one analog output on board

  • Operation also possible without SIMATIC CPU

  • Flexible connections to different automation systems via on board Modbus RTU
    or  Modbus TCP/IP interfaces

  • High resolution of up to  +/- four million parts

  • Measuring rate of 100/120 Hz


Weighing applications
(legal for trade)
Non-automatic weighing instrument
Automatic gravimetric filling instrument 
Automatic catchweighing instrument
Discontinuous totalizing intstrument
Automatic checkweighing instrument
Integration in automation systems
Other systems via Modbus RTU or
Modbus TCP/IP
Communication interfaces (on board)
SIMATIC S7-1200 Bus 
RS485 (Modbus RTU)
Ethernet (Modbus TCP/IP & SIWATOOL)
Internal resolution
Up to +/- 4 million parts
Measuring rate

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