Electronic balance scale

by means of SIEMENS Siwarex WP231 and HMI KTP600.

Posted by george vakfaris on October 05, 2017

There are instances where a compact balance scale does not meet requirements. Sometimes demand is for:

  • a balance integrated into a machine, by means of component
  • triggering various signals according to weight (max/min etc)
  • calculations made by the balancing system value(total weight, average, values logging, or even number of parts being weighted)

In all above cases it is necessary to implement a custom solution based on modules that can be installed within the machine and also be able to interact with it by transmitting or receiving both analog and digital signals.

In this application a balance scale is implemented using the SIEMENS Weighing module SIWAREX WP231, connected to a ZEMIC L6N load cell. For interacting with the module a KTP600 Color touchscreen HMI is used.

The SIWAREX family modules are designed especially for weighting applications. They use a special software for this purpose, called SIWATOOL. It has integrated inputs to connect the load cell - either 4 or 6 wire connection- and it is directly connected to the HMI with an Ethernet cable, since both of these module have integrated WebServers and configurable IPs. On the other hand, it also provides numerous of outputs to be used by the user.

Siemens SIWATOOL software for SIWAREX module adjustment and calibration.

Although many load cells are listed as combatible to SIWAREX, it is found out that many others can communicate it directly without any kind of malfunction. One of them is the ZEMIC L6N 0-30Kg, used in this structure.

Installation of the load cell on the balance screen.

The three line diagram of the 6-wires load cell to the SIWAREX can be found here .

The electrical panel for the SIWAREX module. HMI KTP600 touchscreen, door mounted. The main screen of the application display weight, handling buttons (TARE, ZERO, RESET) and relative information, mostly useful to the programmer. Hotkeys can be used instead (F1-F6).

Text and images by george vakfaris.