SIWAREX WP231
Manual, 07/2014, A5E31238908A-02
145
Integration in SIMATIC S7-1200
11.1.1
A SIWAREX WP231 occupies 32 bytes each in the I/O areas of the CPU. The maximum
number of SIWAREX WP231 weighing modules is defined as follows:
S7-1212 CPU → up to two WP231 weighing modules
S7-1214 CPU → up to eight WP231 weighing modules
S7-1215 CPU → up to eight WP231 weighing modules
S7-1217 CPU → up to eight WP231 weighing modules
Additionally observe the memory requirements for the respective function block calls.
Two types of function block are available: with integrated data record communication (DS
communication) or without data record communication. The difference is that data record
communication permits full access to all parameters (e.g. calibration weights, filters, limits) of
the scale from the S7-1200 CPU and thus from the Touch panel (WP231 firmware 1.0.4 and
higher).
Using the alternative function blocks without data record communication, the current process
values of the scale (weight, status) can be read, and commands (taring, zeroing, etc.) can be
sent. Complete commissioning from the CPU or HMI is not possible since the required
parameters such as the calibration weight cannot be sent. This must be carried out on site
using SIWATOOL.
Table 11- 1 Memory requirements of the function block
FB with DS communication
(FB231 "WP231PR")
FB without DS communication
(FB231 "WP231PE")
YES YES
YES YES
YES NO
Main memory requirements in CPU
14 700 byte + n x 1 700 byte 7 800 byte + n x 400 byte
Load memory requirements in CPU
181 100 byte + n x 40 200 byte 59 000 byte + n x 19 500 byte
n = number of WP231 modules
The function blocks described above including HMI configuring can be downloaded as a
predefined example project ("Ready-for-use") at: Example project "Ready-for-use"
(http://support.automation.siemens.com/WW/view/de/66825585)
The most recent firmware version for the weighing module can be downloaded at: Firmware
(http://support.automation.siemens.com/WW/view/de/75231231)