Weighing module SIWAREX WP521 ST / WP522 ST


SIWAREX WP521 ST and WP522 ST are technology modules for the SIMATIC S7-1500 advanced controller family and are optimally prepared for gravimetric level measurement of silos and hoppers as well as for platform scales. Beside that the weighing modules can also be used for weighing applications in hazardous locations (with Ex-interface SIWAREX IS).
The new technology module is available in two variants: SIWAREX WP521 ST as single channel option for the set-up of one scale and SIWAREX WP522 ST as two-channel option for the set-up of two independent scales.
Integrated in SIMATIC S7-1500 all advantages of the automation system can be used. The free “ready-for-use“ application helps to create fast and easily customer and application specific solutions. Besides that, the service software SIWATOOL V7 enables a quick and user-friendly Different interfaces and connection possibilities are available on board:

SIMATIC S7-1500 system bus, Modbus TCP/IP (Ethernet), Modbus RTU (RS485), four digital outputs and three digital inputs. The integrated monitoring function of the load cells impedance as well as the process and diagnosis alarm functions optimize the plant security resp. plant availability



Basic scales, e.g. platform and hopper scales

Integration in automation systems

SIMATIC S7-1500 (central or distributed with ET200MP)
Other Systems via Modbus RTU or
Modbus TCP/IP

Communication interfaces (on board)

SIMATIC S7-1500 system bus
Per channel 1x RS485 (Modbus RTU, remote display)
Ethernet (Modbus TCP/IP,SIWATOOL)
Per channel 4x digital outputs (24V DC)
Per channel 3x digital inputs (24V DC)

Internal resolution

Up to +/- 4 million parts

Measuring rate

100/120 Hz

Article No.

WP521 ST : 7MH4980-1AA01
WP522 ST : 7MH4980-2AA01


  • Seamless integration of  Integration of platform- and hopper scales into the SIMATIC S7-1500 automation environment

  • Uniform structure and universal communication through the integration in SIMATIC S7-1500

  • Integrated part of TIA portal

  • Resolution of up to +/- 4 million parts

  • Measurement rate of 100/120 Hz (effective interference suppression)

  • Automatic impedance control of the load cells, process and diagnostic alarms

  • Complete parameterization and commissioning via CPU, HMI panel or PC possible

  • Direct use  in  hazardous zone 2