Hello !
While checking a machine installed 2 years ago I noticed that the SDM is reporting that the storage wear has reached 100%.
This PLC having a nonremovable storage, what could I expect for the future ? Total PLC breakdown ?
I have some sort of log that is writing events in a file. I could disable this and switch to AuditTrail, but will the PLC keep working ? Should I replace it ?
Can it be sent for repairs and replace only the integrated storage ?
I can’t give you a final answer but the storage wear is just an identifier on a general scale, so your CPU might be fine for another two years. It’s just the expected lifetime! The bigger your actual wear the more likey is a failure at some point. It’ll work until the memory is broke. I’m not sure if you can check some kind of SMART data of the internal memory… Probably not. There is just the wear level I guess.
In general I would try to outsource data logging to external storages or a database if possible. Especcialy if you have more extensive logs. How many writes per second or minute are we talking about?
About repair / storage replacement: A colleague from B&R will have to answer that.
Best regards,
Hi @krausertm ,
I’ve checked my application and the only thing that is being written on the storage is the AuditTrail archive.
I’m generating custom events sometimes several per second, and the archive gets exported to the storage as soon as the function block reports that its available.
This would be once per day.
This doesn’t sound like a lot of writing data to storage to me, is it ?
Hey @alin.oltean,
no, that sounds fine. So the events are buffered in the RAM and you write once per day? Should not really be an issue… So I’d ask my sales contact for further info / how to process this. If your application provably only writes a few kb / day, the question would be why the storage wear is so high?! I’m not sure what else can influence this value, since it’s not an actual SMART value but some aggregated thing from B&R.
Best regards
Yeah, already did that and created a support ticket. Will get back with info here when I get something back.
Thank you !
Hi Alin, can you update us about your findings and close this topic? 
Hi Jaroslav,
I got today a final answer, which is found also in the help actually, but I missed it:
Quote from 759f3be6-4b34-41ca-900b-382e9529c436:
When using UserROM, the Compact Flash card is burdened by every write procedure. If a large number of events occur within a short period of time, the card may be affected by them. To counteract this, mode “Buffered UserRom” can be used as an alternative. In this case, the content is first cached and then transferred.
I have about 1500 events per day in a 7 hour period. This caused all my CPU’s to reach 100% storage wear. This is a calculated value of course, but B&R recommends to change the PLC in this case (storage is non-removable for Compact-S).
When I replace the PLCs, I will be sure to use Buffered User-ROM setting.