help on WP231 zeroing

Hi,

I am troubleshooting a SIWAREX231 installation. CPU is 6ES7214-1AG40

For zeroing I am loading 1001 to s_CMD2.i_CMD_CODE and then setting s_CMD2.i_CMD_TRIGGER from the HMI. While I am getting s_CMD2.i_CMD_FinishedOK = True everytime zeroing isnt happeing every time.

I have been looking at the manual for any clues and so far found nothing.

How do I solve this?

Thanks in advance

I have attached siwarex configuration file for you reference.

BR//Ashadul

Hi Ashadul,

the thing is that, with the settings you have, the zeroing and also the taring command will be always returned with FinishedOK regardless of the Standstill state. The reason is the parameter "Waiting period (ms)" in the "Calibration Parameters (DR3)"/"Additional Parameters". If this parameter is not 0 the Zeroing/Taring command will be accepted and if the standstill state is not "1" the Siwarex WP232 will wait the "Waiting period", if during the "Waiting period" the standstill state goes to "1" the zeroing will be executed, if the standstill is still not "1" the error "2001 Timeout tare or zero setting" will appear. If you look at the messages in your Siwatool file, you see a lot of these messages.

If you set the "Waiting period" to 0, you will get the FinishedError bit if the standstill is not "1" if you execute the Zeroing or taring.

Regards

ABenno

Hi,

If I understand you correctly and what I have seen happening today; zeroing in my case is failing due to standstill parameters. When the weight value form this system is jumping around and hence standstill state is not true and zeroing is failing then.

What are the reasons for this to happen?

Currently the load cells are wired with unshielded cable. Interference may be one of the reasons.

Are the standstill parameters OK?

Thanks,

Ashadul

Hi Ashadul,

shielding is always an issue that you must care fore.See FAQ: https://support.industry.siemens.com/cs/de/en/view/23923799 

Also with the filter settings you can stabilize the weight value.

With the FW you have there is an issue with the filters, you should update it to the actual one: https://support.industry.siemens.com/cs/de/en/view/75231231 you might also change the function blocks in your PLC program: https://support.industry.siemens.com/cs/ww/en/view/66825585 

The Standstill bit depends on two parameters in DR3/"Additional Paramters"  "Standstill range" and "Standstill time". With your settings "Standstill range" = 1d and "Standstill time" = 2000ms, the weight needs to be in a range of +/-10g(1d) during 2s to be detected as Standstill. See also the manual chapter 8.3.21 ff https://support.industry.siemens.com/cs/de/en/view/90229056 .

Regards

ABenno

Hi,

What does it mean standstill range (in d)? Is in percentage of weight unit?

BR//Ashaduk