Siemens S7-400 Memory Full

[Lare]

Hi Lare,

Thanks for the response.

The dummy output is currently in the temp area.

Not everything is in OB1. It is quite an extensive program.

I tried putting the PLC in stop before downloading the modified OB1, but that didn't work. I tried to recompile everything, but again that didn't work.

I am back at the customer site next week, so will have a look at deleting OB1 online as LD said earlier.

Cheers

Mark

That is odd. You have before done changes to that PLC?
Not sure how download goes on stop plc and does it still need twice memory, but screenshots of memory used from PLC diagnostic windod should give some clue.
Also as Jesper writes. If you haven't done before changes and it pretty old CPU then it can be flash mem which were cheaper but online edits was not possible.


Can you do online edits on different blocks either?
If Q is outside of CPU model suppurted areas then it is not possible to donwload. But it should give different error message than memory full.
But that was sometimes little bit misleading on old s7. Also it should be probably over 32767 IO address range on 400 before limit.


p.s Also remembered that had once years ago bottleneck memory error on 300 download. Download gived that bottleneck warning and sayed that download can have error. First online edit was success. Other online edits gived bigger error and was not possible. We shutted PLC down and restarted and error goed away. When I looked memory used there was still preserve and error didn't repeated afterwards.