WP251-AWI_STATUS.COARSE_SIGNAL zeroing

Hello siwarex community, 

I would like to share the following phenomna with you.

Problem with the siwarex wp251. The system is a S7-1215C, with a siwarex WP251. We do not use directly the output (DQ) of siwarex, we use IO_DATA and specially AWI.status to activate output of PLC.

We use PLC and siwarex for a revamping of bagging machine, output of PLC are filling engine or pneumatic cylinder.

During some filling I can observe a zeroing of the AWI_STATUS.COARSE_SIGNAL. This is causing a reset of the associated PLC output. The Impeller motor is shut off and restart. VERY BAD.

I can also see IO_DATA.PROCESS_VAL_1 (NET WEIGHT) shift to zero and back to normal value.

This phenomena is happening at any time of the filling, beginning, middle, end.

18 siwarex are working, since 6 months, for the moment the phenomena is only visible on 1. But my main concern is that it will affect all and our revamping is not yet finished, in total we will have 24 filling machine equipped with this solution.

Did we make something wrong ?

Possible cause / my hypothesis. Some of them are already in checking process.

• Internal error in the siwarex.
• Malfunction of the siwarex ( damage).
• Too much vibration with impact on wiring connexion or internal malfunction.
• Load cell connexion.
• Firmware update (configured is V1.0, I think V4.0 is available).
• Better use direct output of the siwarex (this is our choice to use PLC output, it works).
• Load cell damage.

I am able to see that I have some Technological messages that are present during part of the filling cycle, not able yet to interpret them but they disappear when we have the "AWI.status" zeroing.

Not able to see yet other siwarex error.

Unable to look to siwatool error report because I don't have it yet, we made all parameters through hmi with the suitable siemens siwarex screens.

I precise that before we made 1 POC (prototype) running one year in real conditions, before deploying to 24 "machines".

This is the first time I see this but it is also because we go deeper and deeper inside siwarex process and we deploy new options inside the PLC.

Thanks for your help,

Nicolas

Hello Siwarexi,

Thanks for your interest.

Effectively it seems that it is only for one plc cycle time. 

Regarding your proposal

1. Yes I can do so but it is not the kind of solution I like. What about root cause of that ? 

2. As we do not use Direct output of the siwarex, I do not know if the phenomena is also occurring there ?

On my side I continue to look at wiring and also connection beetwen plc and siwarex.

Also we should these days have a look with siwatool directly on the card to check error buffer.

Thanks

Nicolas