Siemens S7-400 series memory allocation

Hi Folks,

Was wondering if anyone can offer a bit of guidance. I tried downloading to a 414-2 the other day but was stopped due to lack of memory.

I've attached a screen grab of the offline info and the online info. This is where I'm getting confused... the program has had countless modifications made to it but the CPU has never been in STOP.

From the screen grabs does anyone know if I put the PLC in stop then use the "download user program to memory card" rather than just hitting the download icon would it clear up some space?

Thanks very much.
Inst_tech

You may free up some space by performing a compress, but the way to free most memory is to delete unused code blocks from the plc.

From the block properties, the code requires 126870 bytes of work memory, but the CPU properties show 156976 bytes of work memory allocated - you must have blocks in the plc that have been deleted from the project. Perform a block compare - this will highlight the differences and will indicate blocks that are in the plc but not in the project (and vice versa). All other code blocks should be identical. Delete the blocks that are only in the plc.

ok, I'll give that a go and see if i can get the bytes to match up. Have had an idea, I think the company I work for has a spare CPU so I'll set it up and try downloaded in the two differnet ways I mentioned.

Thanks for your help.
Inst_tech