Siemens SIWAREX WP231 Weighing Electronics


  • Uniform design technology and consistent communication in SIMATIC S7‑1200
  • Uniform configuration with TIA Portal
  • Legal-for-trade according to OIML R-76
  • Operation without SIMATIC CPU possible
  • Direct connection of an operator panel via Ethernet
  • Direct connection of a remote display via RS 485 interface
  • Modbus TCP/IP interface
  • Modbus RTU interface
  • Four digital inputs and outputs, one analog output
  • Measurement of weight or force with a high resolution of up to ±4 million parts and an accuracy of 0.05%
  • Simple adjustment of scale using the SIWATOOL V7 program via the Ethernet interface
  • Recovery point for simple restoration of all parameters
  • Automatic calibration is possible without the need for calibration weights
  • Supports replacement of module without recalibration of scales
  • Use in hazardous area zone 2
  • Connection of digital force compensation load cells from WIPOTEC and Mettler-Toledo (type WM and PBK)

Siemens SIWAREX WP231 Weighing Electronics is a multifunctional weighing module compliant with legal trade standards, suitable for various straightforward weighing and force measurement applications. This compact module is straightforward to set up within the SIMATIC S7-1200 automation system, and it can function independently, even without a SIMATIC CPU.



Integration in automation systems
S7-1200 SIMATIC S7‑1200 system bus
Operator panel and/or automation systems from other vendors Via Ethernet (Modbus TCP/IP) or RS 485 (Modbus RTU)
Communication interfaces SIMATIC S7‑1200 backplane bus
RS 485 (Modbus RTU, Siebert remote display)
Ethernet (SIWATOOL V7, Modbus TCP/IP)
Analog output 0/4 … 20 mA
4 × digital outputs 24 V DC, floating, short-circuit proof
4 × digital inputs 24 V DC, floating
Measuring accuracy
EC type approval as non-automatic weighing instrument, trade class III 3000 d ≥ 0.5 μV/e
Error limit according to DIN 1319-1 of full-scale value at 20 °C ± 10 K (68 °F ± 10 K) 0.05%
Internal resolution Up to ± 4 million parts
Measuring frequency 100 / 120 Hz
Weighing functions
Weight values Gross
Limit values 2 × min/max


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