Siemens S5 115U

Hello,

I have a question that is bugging me, hope someone can shed some light on this

I have a STORK filler that i have just added a new CIP program to, this consists of DB17 in this it calls several other DB's and in turn several PB's, it works great
but for some reason on a power cycle of the PLC the DB 17 becomes empty ? all others are fine just this one, the DB is not written from anywhere, the data in there is read only and is only read from FB10 ?

Any ideas on why this is not keeping its data ?

Cheers in advance

Which CPU?

6ES5 944-7UB21 i believe

Do you have a battery low indicator on the power supply?

Scratch that about the battery, see this if you have an EPROM or EEPROM:

https://support.industry.siemens.co...sing-data-blocks-in-eprom-mode?dti=0&lc=en-WW

S5 115U – CPU 943B / CPU 944 A/B / CPU 945:
The program in the EPROM is loaded into the internal RAM of the CPU with the ID "EPROM". The data blocks can be changed, but after Power ON the contents of the EPROM are again loaded into the RAM, i.e. the changed data blocks are replaced by the data blocks from the EPROM. In order to retain the changes to the data blocks even after Power ON, you have to change the ID of the data blocks from "EPROM" to "RAM". Just as for CPUs 941, 942 and 943A you can create the data blocks using the command "E DB xx".
For changing the block ID see download Entry ID: 3001075 Changing block IDs in CPU 943/944.
For changing the block ID in CPU 945 you have to use the internal operating system service OB250.

Thanks guys, it looks like iv'e found problem, the PLC apparently used to have EEPROM in there, and now is removed, DB 17 is the CIP program in RAM, but there is another DB 117 with no name, looks like that gets copied to DB 17 after a power fail !, DOH should have spotted that

Anyway thanks for the help guys