MT500 series terminals have a retentive memory area called RW (Recipe Word) of 128Kb addresses from 0 to 65535. This area can be used for storing variables that are kept when the terminal is turned off.
Access to RW recipe variables can be done with any variable display / input object in the same way as PLC variables.
Warning! The entry level terminal of the range, MT505 does not have the management of the retentive area and of the real time clock as indicated in this post.