Storing string in ram

Hi how i can store strings and read them also after power down?

You will either need to write the data to an SD card or EEPROM. There is a built-in node sd-log for writing to SD, but I don’t see a node for reading the data back in. There are eeprom libraries you can find here: Libraries — XOD. I don’t have experience with any of these, so I can’t provide much more help.